Return to op.me CVS log

Up to [CSRG BSD Unix] / 42BSD / usr.lib / sendmail / doc

Annotation of 42BSD/usr.lib/sendmail/doc/op.me, revision 1.1

1.1     ! root        1: .if n .ls 2
        !             2: .he 'Sendmail Installation and Operation Guide''%'
        !             3: .fo 'Version 4.2''Last Mod 7/28/83'
        !             4: .nr si 3n
        !             5: .de $0
        !             6: .(x
        !             7: .in \\$3u*3n
        !             8: .ti -3n
        !             9: \\$2.  \\$1
        !            10: .)x
        !            11: ..
        !            12: .de $C
        !            13: .(x
        !            14: .in 0
        !            15: \\$1 \\$2.  \\$3
        !            16: .)x
        !            17: ..
        !            18: .+c
        !            19: .(l C
        !            20: .sz 16
        !            21: .b SENDMAIL
        !            22: .sz 12
        !            23: .sp
        !            24: .b "INSTALLATION AND OPERATION GUIDE"
        !            25: .sz 10
        !            26: .sp
        !            27: .r
        !            28: Eric Allman
        !            29: Britton-Lee, Inc.
        !            30: .sp
        !            31: Version 4.2
        !            32: .)l
        !            33: .sp 2
        !            34: .pp
        !            35: .i Sendmail
        !            36: implements a general purpose internetwork mail routing facility
        !            37: under the UNIX*
        !            38: .(f
        !            39: *UNIX is a trademark of Bell Laboratories.
        !            40: .)f
        !            41: operating system.
        !            42: It is not tied to any one transport protocol \*-
        !            43: its function may be likened to a crossbar switch,
        !            44: relaying messages from one domain into another.
        !            45: In the process,
        !            46: it can do a limited amount of message header editing
        !            47: to put the message into a format that is appropriate
        !            48: for the receiving domain.
        !            49: All of this is done under the control of a configuration file.
        !            50: .pp
        !            51: Due to the requirements of flexibility
        !            52: for
        !            53: .i sendmail ,
        !            54: the configuration file can seem somewhat unapproachable.
        !            55: However, there are only a few basic configurations
        !            56: for most sites,
        !            57: for which standard configuration files have been supplied.
        !            58: Most other configurations
        !            59: can be built by adjusting an existing configuration files
        !            60: incrementally.
        !            61: .pp
        !            62: Although
        !            63: .i sendmail
        !            64: is intended to run
        !            65: without the need for monitoring,
        !            66: it has a number of features
        !            67: that may be used to monitor or adjust the operation
        !            68: under unusual circumstances.
        !            69: These features are described.
        !            70: .pp
        !            71: Section one describes how to do a basic
        !            72: .i sendmail
        !            73: installation.
        !            74: Section two
        !            75: explains the day-to-day information you should know
        !            76: to maintain your mail system.
        !            77: If you have a relatively normal site,
        !            78: these two sections should contain sufficient information
        !            79: for you to install
        !            80: .i sendmail
        !            81: and keep it happy.
        !            82: Section three
        !            83: describes some parameters that may be safely tweaked.
        !            84: Section four
        !            85: has information regarding the command line arguments.
        !            86: Section five
        !            87: contains the nitty-gritty information about the configuration
        !            88: file.
        !            89: This section is for masochists
        !            90: and people who must write their own configuration file.
        !            91: The appendixes give a brief
        !            92: but detailed explanation of a number of features
        !            93: not described in the rest of the paper.
        !            94: .pp
        !            95: The references in this paper are actually found
        !            96: in the companion paper
        !            97: .ul
        !            98: Sendmail \- An Internetwork Mail Router.
        !            99: This other paper should be read before this manual
        !           100: to gain a basic understanding
        !           101: of how the pieces fit together.
        !           102: .sh 1 "BASIC INSTALLATION"
        !           103: .pp
        !           104: There are two basic steps to installing sendmail.
        !           105: The hard part is to build the configuration table.
        !           106: This is a file that sendmail reads when it starts up
        !           107: that describes the mailers it knows about,
        !           108: how to parse addresses,
        !           109: how to rewrite the message header,
        !           110: and the settings of various options.
        !           111: Although the configuration table is quite complex,
        !           112: a configuration can usually be built
        !           113: by adjusting an existing off-the-shelf configuration.
        !           114: The second part is actually doing the installation,
        !           115: i.e., creating the necessary files, etc.
        !           116: .pp
        !           117: The remainder of this section will describe the installation of sendmail
        !           118: assuming you can use one of the existing configurations
        !           119: and that the standard installation parameters are acceptable.
        !           120: All pathnames and examples
        !           121: are given from the root of the
        !           122: .i sendmail
        !           123: subtree.
        !           124: .sh 2 "Off-The-Shelf Configurations"
        !           125: .pp
        !           126: The configuration files
        !           127: are all in the subdirectory
        !           128: .i cf
        !           129: of the sendmail directory.
        !           130: The ones used at Berkeley are in
        !           131: .i m4 \|(1)
        !           132: format;
        !           133: files with names ending
        !           134: .q .m4
        !           135: are
        !           136: .i m4
        !           137: include files,
        !           138: while files with names ending
        !           139: .q .mc
        !           140: are the master files.
        !           141: Files with names ending
        !           142: .q .cf
        !           143: are the
        !           144: .i m4
        !           145: processed versions of the corresponding
        !           146: .q .mc
        !           147: file.
        !           148: .pp
        !           149: Two off the shelf configuration files are supplied
        !           150: to handle the basic cases:
        !           151: .i cf/arpaproto.cf
        !           152: for Arpanet (TCP) sites
        !           153: and
        !           154: .i cf/uucpproto.cf
        !           155: for UUCP sites.
        !           156: These are
        !           157: .i not
        !           158: in
        !           159: .i m4
        !           160: format.
        !           161: The file you need should be copied to a file with the same name
        !           162: as your system,
        !           163: e.g.,
        !           164: .(b
        !           165: cp uucpproto.cf ucsfcgl.cf
        !           166: .)b
        !           167: This file
        !           168: is now ready for installation as
        !           169: .i /usr/lib/sendmail.cf .
        !           170: .sh 2 "Installation Using the Makefile"
        !           171: .pp
        !           172: A makefile exists in the root of the
        !           173: .i sendmail
        !           174: directory that will do all of these steps
        !           175: for a 4.2bsd system.
        !           176: It may have to be slightly tailored
        !           177: for use on other systems.
        !           178: .pp
        !           179: Before using this makefile,
        !           180: you should already have created your configuration file
        !           181: and left it in the file
        !           182: .q cf/\fIsystem\fP.cf
        !           183: where
        !           184: .i system
        !           185: is the name of your system
        !           186: (i.e., what is returned by
        !           187: .i hostname \|(1)).
        !           188: If you do not have
        !           189: .i hostname
        !           190: you can use the declaration
        !           191: .q HOST=\fIsystem\fP
        !           192: on the
        !           193: .i make \|(1)
        !           194: command line.
        !           195: You should also examine the file
        !           196: .i md/config.m4
        !           197: and change the
        !           198: .i m4
        !           199: macros there to reflect any libraries and compilation flags
        !           200: you may need.
        !           201: .pp
        !           202: The basic installation procedure is to type:
        !           203: .(b
        !           204: make
        !           205: make install
        !           206: .)b
        !           207: in the root directory of the
        !           208: .i sendmail
        !           209: distribution.
        !           210: This will make all binaries
        !           211: and install them in the standard places.
        !           212: The second
        !           213: .i make
        !           214: command must be executed as the superuser (root).
        !           215: .sh 2 "Installation by Hand"
        !           216: .pp
        !           217: Along with building a configuration file,
        !           218: you will have to install the
        !           219: .i sendmail
        !           220: startup into your UNIX system.
        !           221: If you are doing this installation
        !           222: in conjunction with a regular Berkeley UNIX install,
        !           223: these steps will already be complete.
        !           224: Many of these steps will have to be executed as the superuser (root).
        !           225: .sh 3 "lib/libsys.a"
        !           226: .pp
        !           227: The library in lib/libsys.a
        !           228: contains some routines that should in some sense
        !           229: be part of the system library.
        !           230: These are the system logging routines
        !           231: and the new directory access routines
        !           232: (if required).
        !           233: If you are not running the new 4.2bsd directory code
        !           234: and do not have the compatibility routines installed in your system library,
        !           235: you should execute the commands:
        !           236: .(b
        !           237: cd lib
        !           238: make ndir
        !           239: .)b
        !           240: This will compile and install the 4.2 compatibility routines
        !           241: in the library.
        !           242: You should then type:
        !           243: .(b
        !           244: cd lib      # if required
        !           245: make
        !           246: .)b
        !           247: This will recompile and fill the library.
        !           248: .sh 3 "/usr/lib/sendmail"
        !           249: .pp
        !           250: The binary for sendmail is located in /usr/lib.
        !           251: There is a version available in the source directory
        !           252: that is probably inadequate for your system.
        !           253: You should plan on recompiling and installing the entire system:
        !           254: .(b
        !           255: cd src
        !           256: rm \-f *.o
        !           257: make
        !           258: cp sendmail /usr/lib
        !           259: .)b
        !           260: .sh 3 "/usr/lib/sendmail.cf"
        !           261: .pp
        !           262: The configuration file
        !           263: that you created earlier
        !           264: should be installed in /usr/lib/sendmail.cf:
        !           265: .(b
        !           266: cp cf/\fIsystem\fP.cf /usr/lib/sendmail.cf
        !           267: .)b
        !           268: .sh 3 "/usr/ucb/newaliases"
        !           269: .pp
        !           270: If you are running delivermail,
        !           271: it is critical that the
        !           272: .i newaliases
        !           273: command be replaced.
        !           274: This can just be a link to
        !           275: .i sendmail :
        !           276: .(b
        !           277: rm \-f /usr/ucb/newaliases
        !           278: ln /usr/lib/sendmail /usr/ucb/newaliases
        !           279: .)b
        !           280: .sh 3 "/usr/lib/sendmail.cf"
        !           281: .pp
        !           282: The configuration file must be installed in /usr/lib.
        !           283: This is described above.
        !           284: .sh 3 "/usr/spool/mqueue"
        !           285: .pp
        !           286: The directory
        !           287: .i /usr/spool/mqueue
        !           288: should be created to hold the mail queue.
        !           289: This directory should be mode 777
        !           290: unless
        !           291: .i sendmail
        !           292: is run setuid,
        !           293: when
        !           294: .i mqueue
        !           295: should be owned by the sendmail owner
        !           296: and mode 755.
        !           297: .sh 3 "/usr/lib/aliases*"
        !           298: .pp
        !           299: The system aliases are held in three files.
        !           300: The file
        !           301: .q /usr/lib/aliases
        !           302: is the master copy.
        !           303: A sample is given in
        !           304: .q lib/aliases
        !           305: which includes some aliases which
        !           306: .i must
        !           307: be defined:
        !           308: .(b
        !           309: cp lib/aliases /usr/lib/aliases
        !           310: .)b
        !           311: You should extend this file with any aliases that are apropos to your system.
        !           312: .pp
        !           313: Normally
        !           314: .i sendmail
        !           315: looks at a version of these files maintained by the
        !           316: .i dbm \|(3)
        !           317: routines.
        !           318: These are stored in
        !           319: .q /usr/lib/aliases.dir
        !           320: and
        !           321: .q /usr/lib/aliases.pag.
        !           322: These can initially be created as empty files,
        !           323: but they will have to be initialized promptly.
        !           324: These should be mode 666 if you are running a reasonably relaxed system:
        !           325: .(b
        !           326: cp /dev/null /usr/lib/aliases.dir
        !           327: cp /dev/null /usr/lib/aliases.pag
        !           328: chmod 666 /usr/lib/aliases.*
        !           329: newaliases
        !           330: .)b
        !           331: .sh 3 "/usr/lib/sendmail.fc"
        !           332: .pp
        !           333: If you intend to install the frozen version of the configuration file
        !           334: (for quick startup)
        !           335: you should create the file /usr/lib/sendmail.fc
        !           336: and initialize it.
        !           337: This step may be safely skipped.
        !           338: .(b
        !           339: cp /dev/null /usr/lib/sendmail.fc
        !           340: /usr/lib/sendmail \-bz
        !           341: .)b
        !           342: .sh 3 "/etc/rc"
        !           343: .pp
        !           344: It will be necessary to start up the sendmail daemon when your system reboots.
        !           345: This daemon performs two functions:
        !           346: it listens on the SMTP socket for connections
        !           347: (to receive mail from a remote system)
        !           348: and it processes the queue periodically
        !           349: to insure that mail gets delivered when hosts come up.
        !           350: .pp
        !           351: Add the following lines to
        !           352: .q /etc/rc
        !           353: (or
        !           354: .q /etc/rc.local
        !           355: as appropriate)
        !           356: in the area where it is starting up the daemons:
        !           357: .(b
        !           358: if [ \-f /usr/lib/sendmail ]; then
        !           359:        (cd /usr/spool/mqueue; rm \-f [lnx]f*)
        !           360:        /usr/lib/sendmail \-bd \-q30m &
        !           361:        echo \-n ' sendmail' >/dev/console
        !           362: fi
        !           363: .)b
        !           364: The
        !           365: .q cd
        !           366: and
        !           367: .q rm
        !           368: commands insure that all lock files have been removed;
        !           369: extraneous lock files may be left around
        !           370: if the system goes down in the middle of processing a message.
        !           371: The line that actually invokes
        !           372: .i sendmail
        !           373: has two flags:
        !           374: .q \-bd
        !           375: causes it to listen on the SMTP port,
        !           376: and
        !           377: .q \-q30m
        !           378: causes it to run the queue every half hour.
        !           379: .pp
        !           380: If you are not running a version of UNIX
        !           381: that supports Berkeley TCP/IP,
        !           382: do not include the
        !           383: .b \-bd
        !           384: flag.
        !           385: .sh 3 "/usr/lib/sendmail.hf"
        !           386: .pp
        !           387: This is the help file used by the SMTP
        !           388: .b HELP
        !           389: command.
        !           390: It should be copied from
        !           391: .q lib/sendmail.hf :
        !           392: .(b
        !           393: cp lib/sendmail.hf /usr/lib
        !           394: .)b
        !           395: .sh 3 "/usr/lib/sendmail.st"
        !           396: .pp
        !           397: If you wish to collect statistics
        !           398: about your mail traffic,
        !           399: you should create the file
        !           400: .q /usr/lib/sendmail.st :
        !           401: .(b
        !           402: cp /dev/null /usr/lib/sendmail.st
        !           403: chmod 666 /usr/lib/sendmail.st
        !           404: .)b
        !           405: This file does not grow.
        !           406: It is printed with the program
        !           407: .q aux/mailstats.
        !           408: .sh 3 "/etc/syslog"
        !           409: .pp
        !           410: You may want to run the
        !           411: .i syslog
        !           412: program
        !           413: (to collect log information about sendmail).
        !           414: This program normally resides in
        !           415: .i /etc/syslog,
        !           416: with support files
        !           417: .i /etc/syslog.conf
        !           418: and
        !           419: .i /etc/syslog.pid .
        !           420: The program is located in the
        !           421: .i aux
        !           422: subdirectory of the
        !           423: .i sendmail
        !           424: distribution.
        !           425: The file
        !           426: .i /etc/syslog.conf
        !           427: describes the file(s) that sendmail will log in.
        !           428: For a complete description of syslog,
        !           429: see the manual page for
        !           430: .i syslog \|(8)
        !           431: (located in
        !           432: .i sendmail/doc
        !           433: on the distribution).
        !           434: .sh 3 "/usr/ucb/newaliases"
        !           435: .pp
        !           436: If
        !           437: .i sendmail
        !           438: is invoked as
        !           439: .q newaliases,
        !           440: it will simulate the
        !           441: .b \-bi
        !           442: flag
        !           443: (i.e., will rebuild the alias database;
        !           444: see below).
        !           445: This should be a link to /usr/lib/sendmail.
        !           446: .sh 3 "/usr/ucb/mailq"
        !           447: .pp
        !           448: If
        !           449: .i sendmail
        !           450: is invoked as
        !           451: .q mailq,
        !           452: it will simulate the
        !           453: .b \-bp
        !           454: flag
        !           455: (i.e.,
        !           456: .i sendmail
        !           457: will print the contents of the mail queue;
        !           458: see below).
        !           459: This should be a link to /usr/lib/sendmail.
        !           460: .sh 1 "NORMAL OPERATIONS"
        !           461: .sh 2 "Quick Configuration Startup"
        !           462: .pp
        !           463: A fast version of the configuration file
        !           464: may be set up by using the
        !           465: .b \-bz
        !           466: flag:
        !           467: .(b
        !           468: /usr/lib/sendmail \-bz
        !           469: .)b
        !           470: This creates the file
        !           471: .i /usr/lib/sendmail.fc
        !           472: (\c
        !           473: .q "frozen configuration" ).
        !           474: This file is an image of
        !           475: .i sendmail 's
        !           476: data space after reading in the configuration file.
        !           477: If this file exists,
        !           478: it is used instead of
        !           479: .i /usr/lib/sendmail.cf
        !           480: .i sendmail.fc
        !           481: must be rebuilt manually every time
        !           482: .i sendmail.cf
        !           483: is changed.
        !           484: .pp
        !           485: The frozen configuration file will be ignored
        !           486: if a
        !           487: .b \-C
        !           488: flag is specified
        !           489: or if sendmail detects that it is out of date.
        !           490: However, the heuristics are not strong
        !           491: so this should not be trusted.
        !           492: .sh 2 "The System Log"
        !           493: .pp
        !           494: The system log is supported by the
        !           495: .i syslog \|(8)
        !           496: program.
        !           497: .sh 3 "Format"
        !           498: .pp
        !           499: Each line in the system log
        !           500: consists of a timestamp,
        !           501: the name of the machine that generated it
        !           502: (for logging from several machines
        !           503: over the ethernet),
        !           504: the word
        !           505: .q sendmail: ,
        !           506: and a message.
        !           507: .sh 3 "Levels"
        !           508: .pp
        !           509: If you have
        !           510: .i syslog \|(8)
        !           511: or an equivalent installed,
        !           512: you will be able to do logging.
        !           513: There is a large amount of information that can be logged.
        !           514: The log is arranged as a succession of levels.
        !           515: At the lowest level
        !           516: only extremely strange situations are logged.
        !           517: At the highest level,
        !           518: even the most mundane and uninteresting events
        !           519: are recorded for posterity.
        !           520: As a convention,
        !           521: log levels under ten
        !           522: are considered
        !           523: .q useful;
        !           524: log levels above ten
        !           525: are usually for debugging purposes.
        !           526: .pp
        !           527: A complete description of the log levels
        !           528: is given in section 4.3.
        !           529: .sh 2 "The Mail Queue"
        !           530: .pp
        !           531: The mail queue should be processed transparently.
        !           532: However, you may find that manual intervention is sometimes necessary.
        !           533: For example,
        !           534: if a major host is down for a period of time
        !           535: the queue may become clogged.
        !           536: Although sendmail ought to recover gracefully when the host comes up,
        !           537: you may find performance unacceptably bad in the meantime.
        !           538: .sh 3 "Printing the queue"
        !           539: .pp
        !           540: The contents of the queue can be printed
        !           541: using the
        !           542: .i mailq
        !           543: command
        !           544: (or by specifying the
        !           545: .b \-bp
        !           546: flag to sendmail):
        !           547: .(b
        !           548: mailq
        !           549: .)b
        !           550: This will produce a listing of the queue id's,
        !           551: the size of the message,
        !           552: the date the message entered the queue,
        !           553: and the sender and recipients.
        !           554: .sh 3 "Format of queue files"
        !           555: .pp
        !           556: All queue files have the form
        !           557: \fIx\fP\|\fBf\fP\fIAA99999\fP
        !           558: where
        !           559: .i AA99999
        !           560: is the
        !           561: .i id
        !           562: for this file
        !           563: and the
        !           564: .i x
        !           565: is a type.
        !           566: The types are:
        !           567: .ip d
        !           568: The data file.
        !           569: The message body (excluding the header) is kept in this file.
        !           570: .ip l
        !           571: The lock file.
        !           572: If this file exists,
        !           573: the job is currently being processed,
        !           574: and a queue run will not process the file.
        !           575: For that reason,
        !           576: an extraneous
        !           577: .b lf
        !           578: file can cause a job to apparently disappear
        !           579: (it will not even time out!).
        !           580: .ip n
        !           581: This file is created when an id is being created.
        !           582: It is a separate file to insure that no mail can ever be destroyed
        !           583: due to a race condition.
        !           584: It should exist for no more than a few milliseconds
        !           585: at any given time.
        !           586: .ip q
        !           587: The queue control file.
        !           588: This file contains the information necessary to process the job.
        !           589: .ip t
        !           590: A temporary file.
        !           591: These are an image of the
        !           592: .b qf
        !           593: file when it is being rebuilt.
        !           594: It should be renamed to a
        !           595: .b qf
        !           596: file very quickly.
        !           597: .ip x
        !           598: A transcript file,
        !           599: existing during the life of a session
        !           600: showing everything that happens
        !           601: during that session.
        !           602: .pp
        !           603: The
        !           604: .b qf
        !           605: file is structured as a series of lines
        !           606: each beginning with a code letter.
        !           607: The lines are as follows:
        !           608: .ip D
        !           609: The name of the data file.
        !           610: There may only be one of these lines.
        !           611: .ip H
        !           612: A header definition.
        !           613: There may be any number of these lines.
        !           614: The order is important:
        !           615: they represent the order in the final message.
        !           616: These use the same syntax
        !           617: as header definitions in the configuration file.
        !           618: .ip R
        !           619: A recipient address.
        !           620: This will normally be completely aliased,
        !           621: but is actually realiased when the job is processed.
        !           622: There will be one line
        !           623: for each recipient.
        !           624: .ip S
        !           625: The sender address.
        !           626: There may only be one of these lines.
        !           627: .ip T
        !           628: The job creation time.
        !           629: This is used to compute when to time out the job.
        !           630: .ip P
        !           631: The current message priority.
        !           632: This is used to order the queue.
        !           633: Higher numbers mean lower priorities.
        !           634: The priority increases
        !           635: as the message sits in the queue.
        !           636: The initial priority depends on the message class
        !           637: and the size of the message.
        !           638: .ip M
        !           639: A message.
        !           640: This line is printed by the
        !           641: .i mailq
        !           642: command,
        !           643: and is generally used to store status information.
        !           644: It can contain any text.
        !           645: .pp
        !           646: As an example,
        !           647: the following is a queue file sent to
        !           648: .q mckusick@calder
        !           649: and
        !           650: .q wnj :
        !           651: .(b
        !           652: DdfA13557
        !           653: Seric
        !           654: T404261372
        !           655: P132
        !           656: Rmckusick@calder
        !           657: Rwnj
        !           658: H?D?date: 23-Oct-82 15:49:32-PDT (Sat)
        !           659: H?F?from: eric (Eric Allman)
        !           660: H?x?full-name: Eric Allman
        !           661: Hsubject: this is an example message
        !           662: Hmessage-id: <[email protected]>
        !           663: Hreceived: by UCBARPA.BERKELEY.ARPA (3.227 [10/22/82])
        !           664:        id A13557; 23-Oct-82 15:49:32-PDT (Sat)
        !           665: Hphone: (415) 548-3211
        !           666: HTo: mckusick@calder, wnj
        !           667: .)b
        !           668: This shows the name of the data file,
        !           669: the person who sent the message,
        !           670: the submission time
        !           671: (in seconds since January 1, 1970),
        !           672: the message priority,
        !           673: the message class,
        !           674: the recipients,
        !           675: and the headers for the message.
        !           676: .sh 3 "Forcing the queue"
        !           677: .pp
        !           678: .i Sendmail
        !           679: should run the queue automatically
        !           680: at intervals.
        !           681: The algorithm is to read and sort the queue,
        !           682: and then to attempt to process all jobs in order.
        !           683: When it attempts to run the job,
        !           684: .i sendmail
        !           685: first checks to see if the job is locked.
        !           686: If so, it ignores the job.
        !           687: .pp
        !           688: There is no attempt to insure that only one queue processor
        !           689: exists at any time,
        !           690: since there is no guarantee that a job cannot take forever
        !           691: to process.
        !           692: Due to the locking algorithm,
        !           693: it is impossible for one job to freeze the queue.
        !           694: However,
        !           695: an uncooperative recipient host
        !           696: or a program recipient
        !           697: that never returns
        !           698: can accumulate many processes in your system.
        !           699: Unfortunately,
        !           700: there is no way to resolve this
        !           701: without violating the protocol.
        !           702: .pp
        !           703: In some cases,
        !           704: you may find that a major host going down
        !           705: for a couple of days
        !           706: may create a prohibitively large queue.
        !           707: This will result in
        !           708: .i sendmail
        !           709: spending an inordinate amount of time
        !           710: sorting the queue.
        !           711: This situation can be fixed by moving the queue to a temporary place
        !           712: and creating a new queue.
        !           713: The old queue can be run later when the offending host returns to service.
        !           714: .pp
        !           715: To do this,
        !           716: it is acceptable to move the entire queue directory:
        !           717: .(b
        !           718: cd /usr/spool
        !           719: mv mqueue omqueue; mkdir mqueue; chmod 777 mqueue
        !           720: .)b
        !           721: You should then kill the existing daemon
        !           722: (since it will still be processing in the old queue directory)
        !           723: and create a new daemon.
        !           724: .pp
        !           725: To run the old mail queue,
        !           726: run the following command:
        !           727: .(b
        !           728: /usr/lib/sendmail \-oQ/usr/spool/omqueue \-q
        !           729: .)b
        !           730: The
        !           731: .b \-oQ
        !           732: flag specifies an alternate queue directory
        !           733: and the
        !           734: .b \-q
        !           735: flag says to just run every job in the queue.
        !           736: If you have a tendency toward voyeurism,
        !           737: you can use the
        !           738: .b \-v
        !           739: flag to watch what is going on.
        !           740: .pp
        !           741: When the queue is finally emptied,
        !           742: you can remove the directory:
        !           743: .(b
        !           744: rmdir /usr/spool/omqueue
        !           745: .)b
        !           746: .sh 2 "The Alias Database"
        !           747: .pp
        !           748: The alias database exists in two forms.
        !           749: One is a text form,
        !           750: maintained in the file
        !           751: .i /usr/lib/aliases.
        !           752: The aliases are of the form
        !           753: .(b
        !           754: name: name1, name2, ...
        !           755: .)b
        !           756: Only local names may be aliased;
        !           757: e.g.,
        !           758: .(b
        !           759: eric@mit-xx: eric@berkeley
        !           760: .)b
        !           761: will not have the desired effect.
        !           762: Aliases may be continued by starting any continuation lines
        !           763: with a space or a tab.
        !           764: Blank lines and lines beginning with a sharp sign
        !           765: (\c
        !           766: .q # )
        !           767: are comments.
        !           768: .pp
        !           769: The second form is processed by the
        !           770: .i dbm \|(3)
        !           771: library.
        !           772: This form is in the files
        !           773: .i /usr/lib/aliases.dir
        !           774: and
        !           775: .i /usr/lib/aliases.pag.
        !           776: This is the form that
        !           777: .i sendmail
        !           778: actually uses to resolve aliases.
        !           779: This technique is used to improve performance.
        !           780: .sh 3 "Rebuilding the alias database"
        !           781: .pp
        !           782: The DBM version of the database
        !           783: may be rebuilt explicitly by executing the command
        !           784: .(b
        !           785: newaliases
        !           786: .)b
        !           787: This is equivalent to giving
        !           788: .i sendmail
        !           789: the
        !           790: .b \-bi
        !           791: flag:
        !           792: .(b
        !           793: /usr/lib/sendmail \-bi
        !           794: .)b
        !           795: .pp
        !           796: If the
        !           797: .q D
        !           798: option is specified in the configuration,
        !           799: .i sendmail
        !           800: will rebuild the alias database automatically
        !           801: if possible
        !           802: when it is out of date.
        !           803: The conditions under which it will do this are:
        !           804: .np
        !           805: The DBM version of the database is mode 666.   -or-
        !           806: .np
        !           807: .i Sendmail
        !           808: is running setuid to root.
        !           809: .lp
        !           810: Auto-rebuild can be dangerous
        !           811: on heavily loaded machines
        !           812: with large alias files;
        !           813: if it might take more than five minutes
        !           814: to rebuild the database,
        !           815: there is a chance that several processes will start the rebuild process
        !           816: simultaneously.
        !           817: .sh 3 "Potential problems"
        !           818: .pp
        !           819: There are a number of problems that can occur
        !           820: with the alias database.
        !           821: They all result from a
        !           822: .i sendmail
        !           823: process accessing the DBM version
        !           824: while it is only partially built.
        !           825: This can happen under two circumstances:
        !           826: One process accesses the database
        !           827: while another process is rebuilding it,
        !           828: or the process rebuilding the database dies
        !           829: (due to being killed or a system crash)
        !           830: before completing the rebuild.
        !           831: .pp
        !           832: Sendmail has two techniques to try to relieve these problems.
        !           833: First, it ignores interrupts while rebuilding the database;
        !           834: this avoids the problem of someone aborting the process
        !           835: leaving a partially rebuilt database.
        !           836: Second,
        !           837: at the end of the rebuild
        !           838: it adds an alias of the form
        !           839: .(b
        !           840: @: @
        !           841: .)b
        !           842: (which is not normally legal).
        !           843: Before sendmail will access the database,
        !           844: it checks to insure that this entry exists\**.
        !           845: .(f
        !           846: \**The
        !           847: .q a
        !           848: option is required in the configuration
        !           849: for this action to occur.
        !           850: This should normally be specified
        !           851: unless you are running
        !           852: .i delivermail
        !           853: in parallel with
        !           854: .i sendmail.
        !           855: .)f
        !           856: It will wait up to five minutes
        !           857: for this entry to appear,
        !           858: at which point it will force a rebuild itself\**.
        !           859: .(f
        !           860: \**Note:
        !           861: the
        !           862: .q D
        !           863: option must be specified in the configuration file
        !           864: for this operation to occur.
        !           865: .)f
        !           866: .sh 3 "List owners"
        !           867: .pp
        !           868: If an error occurs on sending to a certain address,
        !           869: say
        !           870: .q \fIx\fP ,
        !           871: .i sendmail
        !           872: will look for an alias
        !           873: of the form
        !           874: .q owner-\fIx\fP
        !           875: to receive the errors.
        !           876: This is typically useful
        !           877: for a mailing list
        !           878: where the submitter of the list
        !           879: has no control over the maintanence of the list itself;
        !           880: in this case the list maintainer would be the owner of the list.
        !           881: For example:
        !           882: .(b
        !           883: unix-wizards: eric@ucbarpa, wnj@monet, nosuchuser,
        !           884:        sam@matisse
        !           885: owner-unix-wizards: eric@ucbarpa
        !           886: .)b
        !           887: would cause
        !           888: .q eric@ucbarpa
        !           889: to get the error that will occur
        !           890: when someone sends to
        !           891: unix-wizards
        !           892: due to the inclusion of
        !           893: .q nosuchuser
        !           894: on the list.
        !           895: .sh 2 "Per-User Forwarding (.forward Files)"
        !           896: .pp
        !           897: As an alternative to the alias database,
        !           898: any user may put a file with the name
        !           899: .q .forward
        !           900: in his or her home directory.
        !           901: If this file exists,
        !           902: .i sendmail
        !           903: redirects mail for that user
        !           904: to the list of addresses listed in the .forward file.
        !           905: For example, if the home directory for user
        !           906: .q mckusick
        !           907: has a .forward file with contents:
        !           908: .(b
        !           909: mckusick@ernie
        !           910: kirk@calder
        !           911: .)b
        !           912: then any mail arriving for
        !           913: .q mckusick
        !           914: will be redirected to the specified accounts.
        !           915: .sh 2 "Special Header Lines"
        !           916: .pp
        !           917: Several header lines have special interpretations
        !           918: defined by the configuration file.
        !           919: Others have interpretations built into
        !           920: .i sendmail
        !           921: that cannot be changed without changing the code.
        !           922: These builtins are described here.
        !           923: .sh 3 "Return-Receipt-To:"
        !           924: .pp
        !           925: If this header is sent,
        !           926: a message will be sent to any specified addresses
        !           927: when the final delivery is complete.
        !           928: if the mailer has the
        !           929: .b l
        !           930: flag (local delivery) set in the mailer descriptor.
        !           931: .sh 3 "Errors-To:"
        !           932: .pp
        !           933: If errors occur anywhere during processing,
        !           934: this header will cause error messages to go to
        !           935: the listed addresses
        !           936: rather than to the sender.
        !           937: This is intended for mailing lists.
        !           938: .sh 3 "Apparently-To:"
        !           939: .pp
        !           940: If a message comes in with no recipients listed in the message
        !           941: (in a To:, Cc:, or Bcc: line)
        !           942: then
        !           943: .i sendmail
        !           944: will add an
        !           945: .q "Apparently-To:"
        !           946: header line for any recipients it is aware of.
        !           947: This is not put in as a standard recipient line
        !           948: to warn any recipients that the list is not complete.
        !           949: .pp
        !           950: At least one recipient line is required under RFC 822.
        !           951: .sh 1 "ARGUMENTS"
        !           952: .pp
        !           953: The complete list of arguments to
        !           954: .i sendmail
        !           955: is described in detail in Appendix A.
        !           956: Some important arguments are described here.
        !           957: .sh 2 "Queue Interval"
        !           958: .pp
        !           959: The amount of time between forking a process
        !           960: to run through the queue
        !           961: is defined by the
        !           962: .b \-q
        !           963: flag.
        !           964: If you run in mode
        !           965: .b f
        !           966: or
        !           967: .b a
        !           968: this can be relatively large,
        !           969: since it will only be relevant
        !           970: when a host that was down comes back up.
        !           971: If you run in
        !           972: .b q
        !           973: mode
        !           974: it should be relatively short,
        !           975: since it defines the maximum amount of time that a message
        !           976: may sit in the queue.
        !           977: .sh 2 "Daemon Mode"
        !           978: .pp
        !           979: If you allow incoming mail over an IPC connection,
        !           980: you should have a daemon running.
        !           981: This should be set by your
        !           982: .i /etc/rc
        !           983: file using the
        !           984: .b \-bd
        !           985: flag.
        !           986: The
        !           987: .b \-bd
        !           988: flag and the
        !           989: .b \-q
        !           990: flag may be combined in one call:
        !           991: .(b
        !           992: /usr/lib/sendmail \-bd \-q30m
        !           993: .)b
        !           994: .sh 2 "Forcing the Queue"
        !           995: .pp
        !           996: In some cases you may find that the queue has gotten clogged for some reason.
        !           997: You can force a queue run
        !           998: using the
        !           999: .b \-q
        !          1000: flag (with no value).
        !          1001: It is entertaining to use the
        !          1002: .b \-v
        !          1003: flag (verbose)
        !          1004: when this is done to watch what happens:
        !          1005: .(b
        !          1006: /usr/lib/sendmail \-q \-v
        !          1007: .)b
        !          1008: .sh 2 "Debugging"
        !          1009: .pp
        !          1010: There are a fairly large number of debug flags
        !          1011: built into
        !          1012: .i sendmail .
        !          1013: Each debug flag has a number and a level,
        !          1014: where higher levels means to print out more information.
        !          1015: The convention is that levels greater than nine are
        !          1016: .q absurd,
        !          1017: i.e.,
        !          1018: they print out so much information that you wouldn't normally
        !          1019: want to see them except for debugging that particular piece of code.
        !          1020: Debug flags are set using the
        !          1021: .b \-d
        !          1022: option;
        !          1023: the syntax is:
        !          1024: .(b
        !          1025: .ta \w'debug-option  'u
        !          1026: debug-flag:    \fB\-d\fP debug-list
        !          1027: debug-list:    debug-option [ , debug-option ]
        !          1028: debug-option:  debug-range [ . debug-level ]
        !          1029: debug-range:   integer | integer \- integer
        !          1030: debug-level:   integer
        !          1031: .)b
        !          1032: where spaces are for reading ease only.
        !          1033: For example,
        !          1034: .(b
        !          1035: \-d12  Set flag 12 to level 1
        !          1036: \-d12.3        Set flag 12 to level 3
        !          1037: \-d3-17        Set flags 3 through 17 to level 1
        !          1038: \-d3-17.4      Set flags 3 through 17 to level 4
        !          1039: .)b
        !          1040: For a complete list of the available debug flags
        !          1041: you will have to look at the code
        !          1042: (they are too dynamic to keep this documentation up to date).
        !          1043: .sh 2 "Trying a Different Configuration File"
        !          1044: .pp
        !          1045: An alternative configuration file
        !          1046: can be specified using the
        !          1047: .b \-C
        !          1048: flag; for example,
        !          1049: .(b
        !          1050: /usr/lib/sendmail \-Ctest.cf
        !          1051: .)b
        !          1052: uses the configuration file
        !          1053: .i test.cf
        !          1054: instead of the default
        !          1055: .i /usr/lib/sendmail.cf.
        !          1056: If the
        !          1057: .b \-C
        !          1058: flag has no value
        !          1059: it defaults to
        !          1060: .i sendmail.cf
        !          1061: in the current directory.
        !          1062: .sh 2 "Changing the Values of Options"
        !          1063: .pp
        !          1064: Options can be overridden using the
        !          1065: .b \-o
        !          1066: flag.
        !          1067: For example,
        !          1068: .(b
        !          1069: /usr/lib/sendmail \-oT2m
        !          1070: .)b
        !          1071: sets the
        !          1072: .b T
        !          1073: (timeout) option to two minutes
        !          1074: for this run only.
        !          1075: .sh 1 "TUNING"
        !          1076: .pp
        !          1077: There are a number of configuration parameters
        !          1078: you may want to change,
        !          1079: depending on the requirements of your site.
        !          1080: Most of these are set
        !          1081: using an option in the configuration file.
        !          1082: For example,
        !          1083: the line
        !          1084: .q OT3d
        !          1085: sets option
        !          1086: .q T
        !          1087: to the value
        !          1088: .q 3d
        !          1089: (three days).
        !          1090: .sh 2 "Timeouts"
        !          1091: .pp
        !          1092: All time intervals are set
        !          1093: using a scaled syntax.
        !          1094: For example,
        !          1095: .q 10m
        !          1096: represents ten minutes, whereas
        !          1097: .q 2h30m
        !          1098: represents two and a half hours.
        !          1099: The full set of scales is:
        !          1100: .(b
        !          1101: .ta 4n
        !          1102: s      seconds
        !          1103: m      minutes
        !          1104: h      hours
        !          1105: d      days
        !          1106: w      weeks
        !          1107: .)b
        !          1108: .sh 3 "Queue interval"
        !          1109: .pp
        !          1110: The argument to the
        !          1111: .b \-q
        !          1112: flag
        !          1113: specifies how often a subdaemon will run the queue.
        !          1114: This is typically set to between five minutes
        !          1115: and one half hour.
        !          1116: .sh 3 "Read timeouts"
        !          1117: .pp
        !          1118: It is possible to time out when reading the standard input
        !          1119: or when reading from a remote SMTP server.
        !          1120: Technically,
        !          1121: this is not acceptable within the published protocols.
        !          1122: However,
        !          1123: it might be appropriate to set it to something large
        !          1124: in certain environments
        !          1125: (such as an hour).
        !          1126: This will reduce the chance of large numbers of idle daemons
        !          1127: piling up on your system.
        !          1128: This timeout is set using the
        !          1129: .b r
        !          1130: option in the configuration file.
        !          1131: .sh 3 "Message timeouts"
        !          1132: .pp
        !          1133: After sitting in the queue for a few days,
        !          1134: a message will time out.
        !          1135: This is to insure that at least the sender is aware
        !          1136: of the inability to send a message.
        !          1137: The timeout is typically set to three days.
        !          1138: This timeout is set using the
        !          1139: .b T
        !          1140: option in the configuration file.
        !          1141: .pp
        !          1142: The time of submission is set in the queue,
        !          1143: rather than the amount of time left until timeout.
        !          1144: As a result, you can flush messages that have been hanging
        !          1145: for a short period
        !          1146: by running the queue
        !          1147: with a short message timeout.
        !          1148: For example,
        !          1149: .(b
        !          1150: /usr/lib/sendmail \-oT1d \-q
        !          1151: .)b
        !          1152: will run the queue
        !          1153: and flush anything that is one day old.
        !          1154: .sh 2 "Delivery Mode"
        !          1155: .pp
        !          1156: There are a number of delivery modes that
        !          1157: .i sendmail
        !          1158: can operate in,
        !          1159: set by the
        !          1160: .q d
        !          1161: configuration option.
        !          1162: These modes
        !          1163: specify how quickly mail will be delivered.
        !          1164: Legal modes are:
        !          1165: .(b
        !          1166: .ta 4n
        !          1167: i      deliver interactively (synchronously)
        !          1168: b      deliver in background (asynchronously)
        !          1169: q      queue only (don't deliver)
        !          1170: .)b
        !          1171: There are tradeoffs.
        !          1172: Mode
        !          1173: .q i
        !          1174: passes the maximum amount of information to the sender,
        !          1175: but is hardly ever necessary.
        !          1176: Mode
        !          1177: .q q
        !          1178: puts the minimum load on your machine,
        !          1179: but means that delivery may be delayed for up to the queue interval.
        !          1180: Mode
        !          1181: .q b
        !          1182: is probably a good compromise.
        !          1183: However, this mode can cause large numbers of processes
        !          1184: if you have a mailer that takes a long time to deliver a message.
        !          1185: .sh 2 "Log Level"
        !          1186: .pp
        !          1187: The level of logging can be set for sendmail.
        !          1188: The default using a standard configuration table is level 9.
        !          1189: The levels are as follows:
        !          1190: .ip 0
        !          1191: No logging.
        !          1192: .ip 1
        !          1193: Major problems only.
        !          1194: .ip 2
        !          1195: Message collections and failed deliveries.
        !          1196: .ip 3
        !          1197: Successful deliveries.
        !          1198: .ip 4
        !          1199: Messages being defered
        !          1200: (due to a host being down, etc.).
        !          1201: .ip 5
        !          1202: Normal message queueups.
        !          1203: .ip 6
        !          1204: Unusual but benign incidents,
        !          1205: e.g.,
        !          1206: trying to process a locked queue file.
        !          1207: .ip 9
        !          1208: Log internal queue id to external message id mappings.
        !          1209: This can be useful for tracing a message
        !          1210: as it travels between several hosts.
        !          1211: .ip 12
        !          1212: Several messages that are basically only of interest
        !          1213: when debugging.
        !          1214: .ip 16
        !          1215: Verbose information regarding the queue.
        !          1216: .sh 2 "File Modes"
        !          1217: .pp
        !          1218: There are a number of files
        !          1219: that may have a number of modes.
        !          1220: The modes depend on what functionality you want
        !          1221: and the level of security you require.
        !          1222: .sh 3 "To suid or not to suid?"
        !          1223: .pp
        !          1224: .i Sendmail
        !          1225: can safely be made
        !          1226: setuid to root.
        !          1227: At the point where it is about to
        !          1228: .i exec \|(2)
        !          1229: a mailer,
        !          1230: it checks to see if the userid is zero;
        !          1231: if so,
        !          1232: it resets the userid and groupid to a default
        !          1233: (set by the
        !          1234: .b u
        !          1235: and
        !          1236: .b g
        !          1237: options).
        !          1238: (This can be overridden
        !          1239: by setting the
        !          1240: .b S
        !          1241: flag to the mailer
        !          1242: for mailers that are trusted
        !          1243: and must be called as root.)
        !          1244: However,
        !          1245: this will cause mail processing
        !          1246: to be accounted
        !          1247: (using
        !          1248: .i sa \|(8))
        !          1249: to root
        !          1250: rather than to the user sending the mail.
        !          1251: .sh 3 "Temporary file modes"
        !          1252: .pp
        !          1253: The mode of all temporary files that
        !          1254: .i sendmail
        !          1255: creates is determined by the
        !          1256: .q F
        !          1257: option.
        !          1258: Reasonable values for this option are
        !          1259: 0600
        !          1260: and
        !          1261: 0644.
        !          1262: If the more permissive mode is selected,
        !          1263: it will not be necessary to run
        !          1264: .i sendmail
        !          1265: as root at all
        !          1266: (even when running the queue).
        !          1267: .sh 3 "Should my alias database be writable?"
        !          1268: .pp
        !          1269: At Berkeley
        !          1270: we have the alias database
        !          1271: (/usr/lib/aliases*)
        !          1272: mode 666.
        !          1273: There are some dangers inherent in this approach:
        !          1274: any user can add him-/her-self
        !          1275: to any list,
        !          1276: or can
        !          1277: .q steal
        !          1278: any other user's mail.
        !          1279: However,
        !          1280: we have found users to be basically trustworthy,
        !          1281: and the cost of having a read-only database
        !          1282: greater than the expense of finding and eradicating
        !          1283: the rare nasty person.
        !          1284: .pp
        !          1285: The database that
        !          1286: .i sendmail
        !          1287: actually used
        !          1288: is represented by the two files
        !          1289: .i aliases.dir
        !          1290: and
        !          1291: .i aliases.pag
        !          1292: (both in /usr/lib).
        !          1293: The mode on these files should match the mode
        !          1294: on /usr/lib/aliases.
        !          1295: If
        !          1296: .i aliases
        !          1297: is writable
        !          1298: and the
        !          1299: DBM
        !          1300: files
        !          1301: (\c
        !          1302: .i aliases.dir
        !          1303: and
        !          1304: .i aliases.pag )
        !          1305: are not,
        !          1306: users will be unable to reflect their desired changes
        !          1307: through to the actual database.
        !          1308: However,
        !          1309: if
        !          1310: .i aliases
        !          1311: is read-only
        !          1312: and the DBM files are writable,
        !          1313: a slightly sophisticated user
        !          1314: can arrange to steal mail anyway.
        !          1315: .pp
        !          1316: If your DBM files are not writable by the world
        !          1317: or you do not have auto-rebuild enabled
        !          1318: (with the
        !          1319: .q D
        !          1320: option),
        !          1321: then you must be careful to reconstruct the alias database
        !          1322: each time you change the text version:
        !          1323: .(b
        !          1324: newaliases
        !          1325: .)b
        !          1326: If this step is ignored or forgotten
        !          1327: any intended changes will also be ignored or forgotten.
        !          1328: .sh 1 "THE WHOLE SCOOP ON THE CONFIGURATION FILE"
        !          1329: .pp
        !          1330: This section describes the configuration file
        !          1331: in detail,
        !          1332: including hints on how to write one of your own
        !          1333: if you have to.
        !          1334: .pp
        !          1335: There is one point that should be made clear immediately:
        !          1336: the syntax of the configuration file
        !          1337: is designed to be reasonably easy to parse,
        !          1338: since this is done every time
        !          1339: .i sendmail
        !          1340: starts up,
        !          1341: rather than easy for a human to read or write.
        !          1342: On the
        !          1343: .q "future project"
        !          1344: list is a
        !          1345: configuration-file compiler.
        !          1346: .pp
        !          1347: An overview of the configuration file
        !          1348: is given first,
        !          1349: followed by details of the semantics.
        !          1350: .sh 2 "The Syntax"
        !          1351: .pp
        !          1352: The configuration file is organized as a series of lines,
        !          1353: each of which begins with a single character
        !          1354: defining the semantics for the rest of the line.
        !          1355: Lines beginning with a space or a tab
        !          1356: are continuation lines
        !          1357: (although the semantics are not well defined in many places).
        !          1358: Blank lines and lines beginning with a sharp symbol
        !          1359: (`#')
        !          1360: are comments.
        !          1361: .sh 3 "R and S \*- rewriting rules"
        !          1362: .pp
        !          1363: The core of address parsing
        !          1364: are the rewriting rules.
        !          1365: These are an ordered production system.
        !          1366: .i Sendmail
        !          1367: scans through the set of rewriting rules
        !          1368: looking for a match on the left hand side
        !          1369: (LHS)
        !          1370: of the rule.
        !          1371: When a rule matches,
        !          1372: the address is replaced by the right hand side
        !          1373: (RHS)
        !          1374: of the rule.
        !          1375: .pp
        !          1376: There are several sets of rewriting rules.
        !          1377: Some of the rewriting sets are used internally
        !          1378: and must have specific semantics.
        !          1379: Other rewriting sets
        !          1380: do not have specifically assigned semantics,
        !          1381: and may be referenced by the mailer definitions
        !          1382: or by other rewriting sets.
        !          1383: .pp
        !          1384: The syntax of these two commands are:
        !          1385: .(b F
        !          1386: .b S \c
        !          1387: .i n
        !          1388: .)b
        !          1389: Sets the current ruleset being collected to
        !          1390: .i n .
        !          1391: If you begin a ruleset more than once
        !          1392: it deletes the old definition.
        !          1393: .(b F
        !          1394: .b R \c
        !          1395: .i lhs
        !          1396: .i rhs
        !          1397: .i comments
        !          1398: .)b
        !          1399: The
        !          1400: fields must be separated
        !          1401: by at least one tab character;
        !          1402: there may be embedded spaces
        !          1403: in the fields.
        !          1404: The
        !          1405: .i lhs
        !          1406: is a pattern that is applied to the input.
        !          1407: If it matches,
        !          1408: the input is rewritten to the
        !          1409: .i rhs .
        !          1410: The
        !          1411: .i comments
        !          1412: are ignored.
        !          1413: .sh 3 "D \*- define macro"
        !          1414: .pp
        !          1415: Macros are named with a single character.
        !          1416: These may be selected from the entire ASCII set,
        !          1417: but user-defined macros
        !          1418: should be selected from the set of upper case letters only.
        !          1419: Lower case letters
        !          1420: and special symbols
        !          1421: are used internally.
        !          1422: .pp
        !          1423: The syntax for macro definitions is:
        !          1424: .(b F
        !          1425: .b D \c
        !          1426: .i x\|val
        !          1427: .)b
        !          1428: where
        !          1429: .i x
        !          1430: is the name of the macro
        !          1431: and
        !          1432: .i val
        !          1433: is the value it should have.
        !          1434: Macros can be interpolated in most places using the escape sequence
        !          1435: .b $ \c
        !          1436: .i x .
        !          1437: .sh 3 "C and F \*- define classes"
        !          1438: .pp
        !          1439: Classes of words may be defined
        !          1440: to match on the left hand side of rewriting rules.
        !          1441: For example
        !          1442: a class of all local names for this site
        !          1443: might be created
        !          1444: so that attempts to send to oneself
        !          1445: can be eliminated.
        !          1446: These can either be defined directly in the configuration file
        !          1447: or read in from another file.
        !          1448: Classes may be given names
        !          1449: from the set of upper case letters.
        !          1450: Lower case letters and special characters
        !          1451: are reserved for system use.
        !          1452: .pp
        !          1453: The syntax is:
        !          1454: .(b F
        !          1455: .b C \c
        !          1456: .i c\|word1
        !          1457: .i word2...
        !          1458: .br
        !          1459: .b F \c
        !          1460: .i c\|file
        !          1461: [
        !          1462: .i format
        !          1463: ]
        !          1464: .)b
        !          1465: The first form defines the class
        !          1466: .i c
        !          1467: to match any of the named words.
        !          1468: It is permissible to split them among multiple lines;
        !          1469: for example, the two forms:
        !          1470: .(b
        !          1471: CHmonet ucbmonet
        !          1472: .)b
        !          1473: and
        !          1474: .(b
        !          1475: CHmonet
        !          1476: CHucbmonet
        !          1477: .)b
        !          1478: are equivalent.
        !          1479: The second form
        !          1480: reads the elements of the class
        !          1481: .i c
        !          1482: from the named
        !          1483: .i file ;
        !          1484: the
        !          1485: .i format
        !          1486: is a
        !          1487: .i scanf \|(3)
        !          1488: pattern
        !          1489: that should produce a single string.
        !          1490: .sh 3 "M \*- define mailer"
        !          1491: .pp
        !          1492: Programs and interfaces to mailers
        !          1493: are defined in this line.
        !          1494: The format is:
        !          1495: .(b F
        !          1496: .b M \c
        !          1497: .i name ,
        !          1498: {\c
        !          1499: .i field =\c
        !          1500: .i value \|}*
        !          1501: .)b
        !          1502: where
        !          1503: .i name
        !          1504: is the name of the mailer
        !          1505: (used internally only)
        !          1506: and the
        !          1507: .q field=name
        !          1508: pairs define attributes of the mailer.
        !          1509: Fields are:
        !          1510: .(b
        !          1511: .ta 1i
        !          1512: Path   The pathname of the mailer
        !          1513: Flags  Special flags for this mailer
        !          1514: Sender A rewriting set for sender addresses
        !          1515: Recipient      A rewriting set for recipient addresses
        !          1516: Argv   An argument vector to pass to this mailer
        !          1517: Eol    The end-of-line string for this mailer
        !          1518: Maxsize        The maximum message length to this mailer
        !          1519: .)b
        !          1520: Only the first character of the field name is checked.
        !          1521: .sh 3 "H \*- define header"
        !          1522: .pp
        !          1523: The format of the header lines that sendmail inserts into the message
        !          1524: are defined by the
        !          1525: .b H
        !          1526: line.
        !          1527: The syntax of this line is:
        !          1528: .(b F
        !          1529: .b H [\c
        !          1530: .b ? \c
        !          1531: .i mflags \c
        !          1532: .b ? ]\c
        !          1533: .i hname \c
        !          1534: .b :
        !          1535: .i htemplate
        !          1536: .)b
        !          1537: Continuation lines in this spec
        !          1538: are reflected directly into the outgoing message.
        !          1539: The
        !          1540: .i htemplate
        !          1541: is macro expanded before insertion into the message.
        !          1542: If the
        !          1543: .i mflags
        !          1544: (surrounded by question marks)
        !          1545: are specified,
        !          1546: at least one of the specified flags
        !          1547: must be stated in the mailer definition
        !          1548: for this header to be automatically output.
        !          1549: If one of these headers is in the input
        !          1550: it is reflected to the output
        !          1551: regardless of these flags.
        !          1552: .pp
        !          1553: Some headers have special semantics
        !          1554: that will be described below.
        !          1555: .sh 3 "O \*- set option"
        !          1556: .pp
        !          1557: There are a number of
        !          1558: .q random
        !          1559: options that
        !          1560: can be set from a configuration file.
        !          1561: Options are represented by single characters.
        !          1562: The syntax of this line is:
        !          1563: .(b F
        !          1564: .b O \c
        !          1565: .i o\|value
        !          1566: .)b
        !          1567: This sets option
        !          1568: .i o
        !          1569: to be
        !          1570: .i value .
        !          1571: Depending on the option,
        !          1572: .i value
        !          1573: may be a string, an integer,
        !          1574: a boolean
        !          1575: (with legal values
        !          1576: .q t ,
        !          1577: .q T ,
        !          1578: .q f ,
        !          1579: or
        !          1580: .q F ;
        !          1581: the default is TRUE),
        !          1582: or
        !          1583: a time interval.
        !          1584: .sh 3 "T \*- define trusted users"
        !          1585: .pp
        !          1586: Trusted users
        !          1587: are those users who are permitted
        !          1588: to override the sender address
        !          1589: using the
        !          1590: .b \-f
        !          1591: flag.
        !          1592: These typically are
        !          1593: .q root,
        !          1594: .q uucp,
        !          1595: and
        !          1596: .q network,
        !          1597: but on some users it may be convenient
        !          1598: to extend this list to include other users,
        !          1599: perhaps to support
        !          1600: a separate
        !          1601: UUCP
        !          1602: login for each host.
        !          1603: The syntax of this line is:
        !          1604: .(b F
        !          1605: .b T \c
        !          1606: .i user1
        !          1607: .i user2 ...
        !          1608: .)b
        !          1609: There may be more than one of these lines.
        !          1610: .sh 3 "P \*- precedence definitions"
        !          1611: .pp
        !          1612: Values for the
        !          1613: .q "Precedence:"
        !          1614: field may be defined using the
        !          1615: .b P
        !          1616: control line.
        !          1617: The syntax of this field is:
        !          1618: .(b
        !          1619: \fBP\fP\fIname\fP\fB=\fP\fInum\fP
        !          1620: .)b
        !          1621: When the
        !          1622: .i name
        !          1623: is found in a
        !          1624: .q Precedence:
        !          1625: field,
        !          1626: the message class is set to
        !          1627: .i num .
        !          1628: Higher numbers mean higher precedence.
        !          1629: Numbers less than zero
        !          1630: have the special property
        !          1631: that error messages will not be returned.
        !          1632: The default precedence is zero.
        !          1633: For example,
        !          1634: our list of precedences is:
        !          1635: .(b
        !          1636: Pfirst-class=0
        !          1637: Pspecial-delivery=100
        !          1638: Pjunk=\-100
        !          1639: .)b
        !          1640: .sh 2 "The Semantics"
        !          1641: .pp
        !          1642: This section describes the semantics of the configuration file.
        !          1643: .sh 3 "Special macros, conditionals"
        !          1644: .pp
        !          1645: Macros are interpolated
        !          1646: using the construct
        !          1647: .b $ \c
        !          1648: .i x ,
        !          1649: where
        !          1650: .i x
        !          1651: is the name of the macro to be interpolated.
        !          1652: In particular,
        !          1653: lower case letters are reserved to have
        !          1654: special semantics,
        !          1655: used to pass information in or out of sendmail,
        !          1656: and some special characters are reserved to
        !          1657: provide conditionals, etc.
        !          1658: .pp
        !          1659: The following macros
        !          1660: .i must
        !          1661: be defined to transmit information into
        !          1662: .i sendmail:
        !          1663: .(b
        !          1664: .ta 4n
        !          1665: e      The SMTP entry message
        !          1666: j      The \*(lqofficial\*(rq domain name for this site
        !          1667: l      The format of the UNIX from line
        !          1668: n      The name of the daemon (for error messages)
        !          1669: o      The set of "operators" in addresses
        !          1670: q      default format of sender address
        !          1671: .)b
        !          1672: The
        !          1673: .b $e
        !          1674: macro is printed out when SMTP starts up.
        !          1675: The first word must be the
        !          1676: .b $j
        !          1677: macro.
        !          1678: The
        !          1679: .b $j
        !          1680: macro
        !          1681: should be in RFC821 format.
        !          1682: The
        !          1683: .b $l
        !          1684: and
        !          1685: .b $n
        !          1686: macros can be considered constants
        !          1687: except under terribly unusual circumstances.
        !          1688: The
        !          1689: .b $o
        !          1690: macro consists of a list of characters
        !          1691: which will be considered tokens
        !          1692: and which will separate tokens
        !          1693: when doing parsing.
        !          1694: For example, if
        !          1695: .q r
        !          1696: were in the
        !          1697: .b $o
        !          1698: macro, then the input
        !          1699: .q address
        !          1700: would be scanned as three tokens:
        !          1701: .q add,
        !          1702: .q r,
        !          1703: and
        !          1704: .q ess.
        !          1705: Finally, the
        !          1706: .b $q
        !          1707: macro specifies how an address should appear in a message
        !          1708: when it is defaulted.
        !          1709: For example, on our system these definitions are:
        !          1710: .(b
        !          1711: De$j Sendmail $v ready at $b
        !          1712: DnMAILER-DAEMON
        !          1713: DlFrom $g  $d
        !          1714: Do.:%@!^=/
        !          1715: Dq$g$?x ($x)$.
        !          1716: Dj$H.$D
        !          1717: .)b
        !          1718: An acceptable alternative for the
        !          1719: .b $q
        !          1720: macro is
        !          1721: .q "$?x$x $.<$g>" .
        !          1722: These correspond to the following two formats:
        !          1723: .(b
        !          1724: eric@Berkeley (Eric Allman)
        !          1725: Eric Allman <eric@Berkeley>
        !          1726: .)b
        !          1727: .pp
        !          1728: Some macros are defined by
        !          1729: .i sendmail
        !          1730: for interpolation into argv's for mailers
        !          1731: or for other contexts.
        !          1732: These macros are:
        !          1733: .(b
        !          1734: a      The origination date in Arpanet format
        !          1735: b      The current date in Arpanet format
        !          1736: c      The hop count
        !          1737: d      The date in UNIX (ctime) format
        !          1738: f      The sender (from) address
        !          1739: g      The sender address relative to the recipient
        !          1740: h      The recipient host
        !          1741: i      The queue id
        !          1742: p      Sendmail's pid
        !          1743: r      Protocol used
        !          1744: s      Sender's host name
        !          1745: t      A numeric representation of the current time
        !          1746: u      The recipient user
        !          1747: v      The version number of sendmail
        !          1748: w      The hostname of this site
        !          1749: x      The full name of the sender
        !          1750: y      The id of the sender's tty
        !          1751: z      The home directory of the recipient
        !          1752: .)b
        !          1753: .pp
        !          1754: There are three types of dates that can be used.
        !          1755: The
        !          1756: .b $a
        !          1757: and
        !          1758: .b $b
        !          1759: macros are in Arpanet format;
        !          1760: .b $a
        !          1761: is the time as extracted from the
        !          1762: .q Date:
        !          1763: line of the message
        !          1764: (if there was one),
        !          1765: and
        !          1766: .b $b
        !          1767: is the current date and time
        !          1768: (used for postmarks).
        !          1769: If no
        !          1770: .q Date:
        !          1771: line is found in the incoming message,
        !          1772: .b $a
        !          1773: is set to the current time also.
        !          1774: The
        !          1775: .b $d
        !          1776: macro is equivalent to the
        !          1777: .b $a
        !          1778: macro in UNIX
        !          1779: (ctime)
        !          1780: format.
        !          1781: .pp
        !          1782: The
        !          1783: .b $f
        !          1784: macro is the id of the sender
        !          1785: as originally determined;
        !          1786: when mailing to a specific host
        !          1787: the
        !          1788: .b $g
        !          1789: macro is set to the address of the sender
        !          1790: .ul
        !          1791: relative to the recipient.
        !          1792: For example,
        !          1793: if I send to
        !          1794: .q bollard@matisse
        !          1795: from the machine
        !          1796: .q ucbarpa
        !          1797: the
        !          1798: .b $f
        !          1799: macro will be
        !          1800: .q eric
        !          1801: and the
        !          1802: .b $g
        !          1803: macro will be
        !          1804: .q eric@ucbarpa.
        !          1805: .pp
        !          1806: The
        !          1807: .b $x
        !          1808: macro is set to the full name of the sender.
        !          1809: This can be determined in several ways.
        !          1810: It can be passed as flag to
        !          1811: .i sendmail.
        !          1812: The second choice is the value of the
        !          1813: .q Full-name:
        !          1814: line in the header if it exists,
        !          1815: and the third choice is the comment field
        !          1816: of a
        !          1817: .q From:
        !          1818: line.
        !          1819: If all of these fail,
        !          1820: and if the message is being originated locally,
        !          1821: the full name is looked up in the
        !          1822: .i /etc/passwd
        !          1823: file.
        !          1824: .pp
        !          1825: When sending,
        !          1826: the
        !          1827: .b $h ,
        !          1828: .b $u ,
        !          1829: and
        !          1830: .b $z
        !          1831: macros get set to the host, user, and home directory
        !          1832: (if local)
        !          1833: of the recipient.
        !          1834: The first two are set from the
        !          1835: .b $@
        !          1836: and
        !          1837: .b $:
        !          1838: part of the rewriting rules, respectively.
        !          1839: .pp
        !          1840: The
        !          1841: .b $p
        !          1842: and
        !          1843: .b $t
        !          1844: macros are used to create unique strings
        !          1845: (e.g., for the
        !          1846: .q Message-Id:
        !          1847: field).
        !          1848: The
        !          1849: .b $i
        !          1850: macro is set to the queue id on this host;
        !          1851: if put into the timestamp line
        !          1852: it can be extremely useful for tracking messages.
        !          1853: The
        !          1854: .b $y
        !          1855: macro is set to the id of the terminal of the sender
        !          1856: (if known);
        !          1857: some systems like to put this
        !          1858: in the Unix
        !          1859: .q From
        !          1860: line.
        !          1861: The
        !          1862: .b $v
        !          1863: macro is set to be the version number of
        !          1864: .i sendmail ;
        !          1865: this is normally put in timestamps
        !          1866: and has been proven extremely useful for debugging.
        !          1867: The
        !          1868: .b $w
        !          1869: macro is set to the name of this host
        !          1870: if it can be determined.
        !          1871: The
        !          1872: .b $c
        !          1873: field is set to the
        !          1874: .q "hop count,"
        !          1875: i.e., the number of times this message has been processed.
        !          1876: This can be determined
        !          1877: by the
        !          1878: .b \-h
        !          1879: flag on the command line
        !          1880: or by counting the timestamps in the message.
        !          1881: .pp
        !          1882: The
        !          1883: .b $r
        !          1884: and
        !          1885: .b $s
        !          1886: fields are set to the protocol used to communicate with sendmail
        !          1887: and the sending hostname;
        !          1888: these are not supported in the current version.
        !          1889: .pp
        !          1890: Conditionals can be specified using the syntax:
        !          1891: .(b
        !          1892: $?x text1 $| text2 $.
        !          1893: .)b
        !          1894: This interpolates
        !          1895: .i text1
        !          1896: if the macro
        !          1897: .b $x
        !          1898: is set,
        !          1899: and
        !          1900: .i text2
        !          1901: otherwise.
        !          1902: The
        !          1903: .q else
        !          1904: (\c
        !          1905: .b $| )
        !          1906: clause may be omitted.
        !          1907: .sh 3 "Special classes"
        !          1908: .pp
        !          1909: The class
        !          1910: .b $=w
        !          1911: is set to be the set of all names
        !          1912: this host is known by.
        !          1913: This can be used to delete local hostnames.
        !          1914: .sh 3 "The left hand side"
        !          1915: .pp
        !          1916: The left hand side of rewriting rules contains a pattern.
        !          1917: Normal words are simply matched directly.
        !          1918: Metasyntax is introduced using a dollar sign.
        !          1919: The metasymbols are:
        !          1920: .(b
        !          1921: .ta \w'\fB$=\fP\fIx\fP  'u
        !          1922: \fB$*\fP       Match zero or more tokens
        !          1923: \fB$+\fP       Match one or more tokens
        !          1924: \fB$\-\fP      Match exactly one token
        !          1925: \fB$=\fP\fIx\fP        Match any token in class \fIx\fP
        !          1926: \fB$~\fP\fIx\fP        Match any token not in class \fIx\fP
        !          1927: .)b
        !          1928: If any of these match,
        !          1929: they are assigned to the symbol
        !          1930: .b $ \c
        !          1931: .i n
        !          1932: for replacement on the right hand side,
        !          1933: where
        !          1934: .i n
        !          1935: is the index in the LHS.
        !          1936: For example,
        !          1937: if the LHS:
        !          1938: .(b
        !          1939: $\-:$+
        !          1940: .)b
        !          1941: is applied to the input:
        !          1942: .(b
        !          1943: UCBARPA:eric
        !          1944: .)b
        !          1945: the rule will match, and the values passed to the RHS will be:
        !          1946: .(b
        !          1947: .ta 4n
        !          1948: $1     UCBARPA
        !          1949: $2     eric
        !          1950: .)b
        !          1951: .sh 3 "The right hand side"
        !          1952: .pp
        !          1953: When the right hand side of a rewriting rule matches,
        !          1954: the input is deleted and replaced by the right hand side.
        !          1955: Tokens are copied directly from the RHS
        !          1956: unless they are begin with a dollar sign.
        !          1957: Metasymbols are:
        !          1958: .(b
        !          1959: .ta \w'$#mailer  'u
        !          1960: \fB$\fP\fIn\fP Substitute indefinite token \fIn\fP from LHS
        !          1961: \fB$>\fP\fIn\fP        \*(lqCall\*(rq ruleset \fIn\fP
        !          1962: \fB$#\fP\fImailer\fP   Resolve to \fImailer\fP
        !          1963: \fB$@\fP\fIhost\fP     Specify \fIhost\fP
        !          1964: \fB$:\fP\fIuser\fP     Specify \fIuser\fP
        !          1965: .)b
        !          1966: .pp
        !          1967: The
        !          1968: .b $ \c
        !          1969: .i n
        !          1970: syntax substitutes the corresponding value from a
        !          1971: .b $+ ,
        !          1972: .b $\- ,
        !          1973: .b $* ,
        !          1974: .b $= ,
        !          1975: or
        !          1976: .b $~
        !          1977: match on the LHS.
        !          1978: It may be used anywhere.
        !          1979: .pp
        !          1980: The
        !          1981: .b $> \c
        !          1982: .i n
        !          1983: syntax
        !          1984: causes the remainder of the line to be substituted as usual
        !          1985: and then passed as the argument to ruleset
        !          1986: .i n .
        !          1987: The final value of ruleset
        !          1988: .i n
        !          1989: then becomes
        !          1990: the substitution for this rule.
        !          1991: .pp
        !          1992: The
        !          1993: .b $#
        !          1994: syntax should
        !          1995: .i only
        !          1996: be used in ruleset zero.
        !          1997: It causes evaluation of the ruleset to terminate immediately,
        !          1998: and signals to sendmail that the address has completely resolved.
        !          1999: The complete syntax is:
        !          2000: .(b
        !          2001: \fB$#\fP\fImailer\fP\fB$@\fP\fIhost\fP\fB$:\fP\fIuser\fP
        !          2002: .)b
        !          2003: This specifies the
        !          2004: {mailer, host, user}
        !          2005: 3-tuple necessary to direct the mailer.
        !          2006: If the mailer is local
        !          2007: the host part may be omitted.
        !          2008: The
        !          2009: .i mailer
        !          2010: and
        !          2011: .i host
        !          2012: must be a single word,
        !          2013: but the
        !          2014: .i user
        !          2015: may be multi-part.
        !          2016: .pp
        !          2017: A RHS may also be preceeded by a
        !          2018: .b $@
        !          2019: or a
        !          2020: .b $:
        !          2021: to control evaluation.
        !          2022: A
        !          2023: .b $@
        !          2024: prefix causes the ruleset to return with the remainder of the RHS
        !          2025: as the value.
        !          2026: A
        !          2027: .b $:
        !          2028: prefix causes the rule to terminate immediately,
        !          2029: but the ruleset to continue;
        !          2030: this can be used to avoid continued application of a rule.
        !          2031: The prefix is stripped before continuing.
        !          2032: .pp
        !          2033: The
        !          2034: .b $@
        !          2035: and
        !          2036: .b $:
        !          2037: prefixes may preceed a
        !          2038: .b $>
        !          2039: spec;
        !          2040: for example:
        !          2041: .(b
        !          2042: .ta 8n
        !          2043: R$+    $:$>7$1
        !          2044: .)b
        !          2045: matches anything,
        !          2046: passes that to ruleset seven,
        !          2047: and continues;
        !          2048: the
        !          2049: .b $:
        !          2050: is necessary to avoid an infinite loop.
        !          2051: .sh 3 "Semantics of rewriting rule sets"
        !          2052: .pp
        !          2053: There are five rewriting sets
        !          2054: that have specific semantics.
        !          2055: These are related as depicted by figure 2.
        !          2056: .(z
        !          2057: .hl
        !          2058: .ie t .sp 2i
        !          2059: .el \{\
        !          2060: .(c
        !          2061:                     +---+
        !          2062:                  -->| 0 |-->resolved address
        !          2063:                 /   +---+
        !          2064:                /            +---+   +---+
        !          2065:               /        ---->| 1 |-->| S |--
        !          2066:        +---+ / +---+  /     +---+   +---+  \e    +---+
        !          2067: addr-->| 3 |-->| D |--                      --->| 4 |-->msg
        !          2068:        +---+   +---+  \e     +---+   +---+  /    +---+
        !          2069:                         --->| 2 |-->| R |--
        !          2070:                             +---+   +---+
        !          2071: .)c
        !          2072: 
        !          2073: .ce
        !          2074: Figure 2 \*- Rewriting set semantics
        !          2075: .(c
        !          2076: D \*- sender domain addition
        !          2077: S \*- mailer-specific sender rewriting
        !          2078: R \*- mailer-specific recipient rewriting
        !          2079: .)c
        !          2080: .\}
        !          2081: .hl
        !          2082: .)z
        !          2083: .pp
        !          2084: Ruleset three
        !          2085: should turn the address into
        !          2086: .q "canonical form."
        !          2087: This form should have the basic syntax:
        !          2088: .(b
        !          2089: local-part@host-domain-spec
        !          2090: .)b
        !          2091: If no
        !          2092: .q @
        !          2093: sign is specified,
        !          2094: then the
        !          2095: host-domain-spec
        !          2096: .i may
        !          2097: be appended from the
        !          2098: sender address
        !          2099: (if the
        !          2100: .b C
        !          2101: flag is set in the mailer definition
        !          2102: corresponding to the
        !          2103: .i sending
        !          2104: mailer).
        !          2105: Ruleset three
        !          2106: is applied by sendmail
        !          2107: before doing anything with any address.
        !          2108: .pp
        !          2109: Ruleset zero
        !          2110: is applied after ruleset three
        !          2111: to addresses that are going to actually specify recipients.
        !          2112: It must resolve to a
        !          2113: .i "{mailer, host, user}"
        !          2114: triple.
        !          2115: The
        !          2116: .i mailer
        !          2117: must be defined in the mailer definitions
        !          2118: from the configuration file.
        !          2119: The
        !          2120: .i host
        !          2121: is defined into the
        !          2122: .b $h
        !          2123: macro
        !          2124: for use in the argv expansion of the specified mailer.
        !          2125: .pp
        !          2126: Rulesets one and two
        !          2127: are applied to all sender and recipient addresses respectively.
        !          2128: They are applied before any specification
        !          2129: in the mailer definition.
        !          2130: They must never resolve.
        !          2131: .pp
        !          2132: Ruleset four is applied to all addresses
        !          2133: in the message.
        !          2134: It is typically used
        !          2135: to translate internal to external form.
        !          2136: .sh 3 "Mailer flags etc."
        !          2137: .pp
        !          2138: There are a number of flags that may be associated with each mailer,
        !          2139: each identified by a letter of the alphabet.
        !          2140: Many of them are assigned semantics internally.
        !          2141: These are detailed in Appendix C.
        !          2142: Any other flags may be used freely
        !          2143: to conditionally assign headers to messages
        !          2144: destined for particular mailers.
        !          2145: .sh 3 "The \*(lqerror\*(rq mailer"
        !          2146: .pp
        !          2147: The mailer with the special name
        !          2148: .q error
        !          2149: can be used to generate a user error.
        !          2150: The (optional) host field is a numeric exit status to be returned,
        !          2151: and the user field is a message to be printed.
        !          2152: For example, the entry:
        !          2153: .(b
        !          2154: $#error$:Host unknown in this domain
        !          2155: .)b
        !          2156: on the RHS of a rule
        !          2157: will cause the specified error to be generated
        !          2158: if the LHS matches.
        !          2159: This mailer is only functional in ruleset zero.
        !          2160: .sh 2 "Building a Configuration File From Scratch"
        !          2161: .pp
        !          2162: Building a configuration table from scratch is an extremely difficult job.
        !          2163: Fortunately,
        !          2164: it is almost never necessary to do so;
        !          2165: nearly every situation that may come up
        !          2166: may be resolved by changing an existing table.
        !          2167: In any case,
        !          2168: it is critical that you understand what it is that you are trying to do
        !          2169: and come up with a philosophy for the configuration table.
        !          2170: This section is intended to explain what the real purpose
        !          2171: of a configuration table is
        !          2172: and to give you some ideas
        !          2173: for what your philosophy might be.
        !          2174: .sh 3 "What you are trying to do"
        !          2175: .pp
        !          2176: The configuration table has three major purposes.
        !          2177: The first and simplest
        !          2178: is to set up the environment for
        !          2179: .i sendmail .
        !          2180: This involves setting the options,
        !          2181: defining a few critical macros,
        !          2182: etc.
        !          2183: Since these are described in other places,
        !          2184: we will not go into more detail here.
        !          2185: .pp
        !          2186: The second purpose is to rewrite addresses in the message.
        !          2187: This should typically be done in two phases.
        !          2188: The first phase maps addresses in any format
        !          2189: into a canonical form.
        !          2190: This should be done in ruleset three.
        !          2191: The second phase maps this canonical form
        !          2192: into the syntax appropriate for the receiving mailer.
        !          2193: .i Sendmail
        !          2194: does this in three subphases.
        !          2195: Rulesets one and two
        !          2196: are applied to all sender and recipient addresses respectively.
        !          2197: After this,
        !          2198: you may specify per-mailer rulesets
        !          2199: for both sender and recipient addresses;
        !          2200: this allows mailer-specific customization.
        !          2201: Finally,
        !          2202: ruleset four is applied to do any default conversion
        !          2203: to external form.
        !          2204: .pp
        !          2205: The third purpose
        !          2206: is to map addresses into the actual set of instructions
        !          2207: necessary to get the message delivered.
        !          2208: Ruleset zero must resolve to the internal form,
        !          2209: which is in turn used as a pointer to a mailer descriptor.
        !          2210: The mailer descriptor describes the interface requirements
        !          2211: of the mailer.
        !          2212: .sh 3 "Philosophy"
        !          2213: .pp
        !          2214: The particular philosophy you choose will depend heavily
        !          2215: on the size and structure of your organization.
        !          2216: I will present a few possible philosophies here.
        !          2217: .pp
        !          2218: One general point applies to all of these philosophies:
        !          2219: it is almost always a mistake
        !          2220: to try to do full name resolution.
        !          2221: For example,
        !          2222: if you are trying to get names of the form
        !          2223: .q user@host
        !          2224: to the Arpanet,
        !          2225: it does not pay to route them to
        !          2226: .q xyzvax!decvax!ucbvax!c70:user@host
        !          2227: since you then depend on several links not under your control.
        !          2228: The best approach to this problem
        !          2229: is to simply forward to
        !          2230: .q xyzvax!user@host
        !          2231: and let xyzvax
        !          2232: worry about it from there.
        !          2233: In summary,
        !          2234: just get the message closer to the destination,
        !          2235: rather than determining the full path.
        !          2236: .sh 4 "Large site, many hosts \*- minimum information"
        !          2237: .pp
        !          2238: Berkeley is an example of a large site,
        !          2239: i.e., more than two or three hosts.
        !          2240: We have decided that the only reasonable philosophy
        !          2241: in our environment
        !          2242: is to designate one host as the guru for our site.
        !          2243: It must be able to resolve any piece of mail it receives.
        !          2244: The other sites should have the minimum amount of information
        !          2245: they can get away with.
        !          2246: In addition,
        !          2247: any information they do have
        !          2248: should be hints rather than solid information.
        !          2249: .pp
        !          2250: For example,
        !          2251: a typical site on our local ether network is
        !          2252: .q monet.
        !          2253: Monet has a list of known ethernet hosts;
        !          2254: if it receives mail for any of them,
        !          2255: it can do direct delivery.
        !          2256: If it receives mail for any unknown host,
        !          2257: it just passes it directly to
        !          2258: .q ucbvax,
        !          2259: our master host.
        !          2260: Ucbvax may determine that the host name is illegal
        !          2261: and reject the message,
        !          2262: or may be able to do delivery.
        !          2263: However, it is important to note that when a new ethernet host is added,
        !          2264: the only host that
        !          2265: .i must
        !          2266: have its tables updated
        !          2267: is ucbvax;
        !          2268: the others
        !          2269: .i may
        !          2270: be updated as convenient,
        !          2271: but this is not critical.
        !          2272: .pp
        !          2273: This picture is slightly muddied
        !          2274: due to network connections that are not actually located
        !          2275: on ucbvax.
        !          2276: For example,
        !          2277: our TCP connection is currently on
        !          2278: .q ucbarpa.
        !          2279: However,
        !          2280: monet
        !          2281: .i "does not"
        !          2282: know about this;
        !          2283: the information is hidden totally between ucbvax and ucbarpa.
        !          2284: Mail going from monet to a TCP host
        !          2285: is transfered via the ethernet
        !          2286: from monet to ucbvax,
        !          2287: then via the ethernet from ucbvax to ucbarpa,
        !          2288: and then is submitted to the Arpanet.
        !          2289: Although this involves some extra hops,
        !          2290: we feel this is an acceptable tradeoff.
        !          2291: .pp
        !          2292: An interesting point is that it would be possible
        !          2293: to update monet
        !          2294: to send TCP mail directly to ucbarpa
        !          2295: if the load got too high;
        !          2296: if monet failed to note a host as a TCP host
        !          2297: it would go via ucbvax as before,
        !          2298: and if monet incorrectly sent a message to ucbarpa
        !          2299: it would still be sent by ucbarpa
        !          2300: to ucbvax as before.
        !          2301: The only problem that can occur is loops,
        !          2302: as if ucbarpa thought that ucbvax had the TCP connection
        !          2303: and vice versa.
        !          2304: For this reason,
        !          2305: updates should
        !          2306: .i always
        !          2307: happen to the master host first.
        !          2308: .pp
        !          2309: This philosophy results as much from the need
        !          2310: to have a single source for the configuration files
        !          2311: (typically built using
        !          2312: .i m4 \|(1)
        !          2313: or some similar tool)
        !          2314: as any logical need.
        !          2315: Maintaining more than three separate tables by hand
        !          2316: is essentially an impossible job.
        !          2317: .sh 4 "Small site \*- complete information"
        !          2318: .pp
        !          2319: A small site
        !          2320: (two or three hosts)
        !          2321: may find it more reasonable to have complete information
        !          2322: at each host.
        !          2323: This would require that each host
        !          2324: know exactly where each network connection is,
        !          2325: possibly including the names of each host on that network.
        !          2326: As long as the site remains small
        !          2327: and the the configuration remains relatively static,
        !          2328: the update problem will probably not be too great.
        !          2329: .sh 4 "Single host"
        !          2330: .pp
        !          2331: This is in some sense the trivial case.
        !          2332: The only major issue is trying to insure that you don't
        !          2333: have to know too much about your environment.
        !          2334: For example,
        !          2335: if you have a UUCP connection
        !          2336: you might find it useful to know about the names of hosts
        !          2337: connected directly to you,
        !          2338: but this is really not necessary
        !          2339: since this may be determined from the syntax.
        !          2340: .sh 3 "Relevant issues"
        !          2341: .pp
        !          2342: The canonical form you use
        !          2343: should almost certainly be as specified in
        !          2344: the Arpanet protocols
        !          2345: RFC819 and RFC822.
        !          2346: Copies of these RFC's are included on the
        !          2347: .i sendmail
        !          2348: tape
        !          2349: as
        !          2350: .i doc/rfc819.lpr
        !          2351: and
        !          2352: .i doc/rfc822.lpr .
        !          2353: .pp
        !          2354: RFC822
        !          2355: describes the format of the mail message itself.
        !          2356: .i Sendmail
        !          2357: follows this RFC closely,
        !          2358: to the extent that many of the standards described in this document
        !          2359: can not be changed without changing the code.
        !          2360: In particular,
        !          2361: the following characters have special interpretations:
        !          2362: .(b
        !          2363: < > ( ) " \e
        !          2364: .)b
        !          2365: Any attempt to use these characters for other than their RFC822
        !          2366: purpose in addresses is probably doomed to disaster.
        !          2367: .pp
        !          2368: RFC819
        !          2369: describes the specifics of the domain-based addressing.
        !          2370: This is touched on in RFC822 as well.
        !          2371: Essentially each host is given a name
        !          2372: which is a right-to-left dot qualified pseudo-path
        !          2373: from a distinguished root.
        !          2374: The elements of the path need not be physical hosts;
        !          2375: the domain is logical rather than physical.
        !          2376: For example,
        !          2377: at Berkeley
        !          2378: one legal host is
        !          2379: .q a.cc.berkeley.arpa ;
        !          2380: reading from right to left,
        !          2381: .q arpa
        !          2382: is a top level domain
        !          2383: (related to, but not limited to, the physical Arpanet),
        !          2384: .q berkeley
        !          2385: is both an Arpanet host and a logical domain
        !          2386: which is actually interpreted by
        !          2387: a host called ucbvax
        !          2388: (which is actually just the
        !          2389: .q "major"
        !          2390: host for this domain),
        !          2391: .q cc
        !          2392: represents the Computer Center,
        !          2393: (in this case a strictly logical entity),
        !          2394: and
        !          2395: .q a
        !          2396: is a host in the Computer Center;
        !          2397: this particular host happens to be connected
        !          2398: via berknet,
        !          2399: but other hosts might be connected via one of two ethernets
        !          2400: or some other network.
        !          2401: .pp
        !          2402: Beware when reading RFC819
        !          2403: that there are a number of errors in it.
        !          2404: .sh 3 "How to proceed"
        !          2405: .pp
        !          2406: Once you have decided on a philosophy,
        !          2407: it is worth examining the available configuration tables
        !          2408: to decide if any of them are close enough
        !          2409: to steal major parts of.
        !          2410: Even under the worst of conditions,
        !          2411: there is a fair amount of boiler plate that can be collected safely.
        !          2412: .pp
        !          2413: The next step is to build ruleset three.
        !          2414: This will be the hardest part of the job.
        !          2415: Beware of doing too much to the address in this ruleset,
        !          2416: since anything you do will reflect through
        !          2417: to the message.
        !          2418: In particular,
        !          2419: stripping of local domains is best deferred,
        !          2420: since this can leave you with addresses with no domain spec at all.
        !          2421: Since
        !          2422: .i sendmail
        !          2423: likes to append the sending domain to addresses with no domain,
        !          2424: this can change the semantics of addresses.
        !          2425: Also try to avoid
        !          2426: fully qualifying domains in this ruleset.
        !          2427: Although technically legal,
        !          2428: this can lead to unpleasantly and unnecessarily long addresses
        !          2429: reflected into messages.
        !          2430: The Berkeley configuration files
        !          2431: define ruleset nine
        !          2432: to qualify domain names and strip local domains.
        !          2433: This is called from ruleset zero
        !          2434: to get all addresses into a cleaner form.
        !          2435: .pp
        !          2436: Once you have ruleset three finished,
        !          2437: the other rulesets should be relatively trivial.
        !          2438: If you need hints,
        !          2439: examine the supplied configuration tables.
        !          2440: .sh 3 "Testing the rewriting rules \*- the \-bt flag"
        !          2441: .pp
        !          2442: When you build a configuration table,
        !          2443: you can do a certain amount of testing
        !          2444: using the
        !          2445: .q "test mode"
        !          2446: of
        !          2447: .i sendmail .
        !          2448: For example,
        !          2449: you could invoke
        !          2450: .i sendmail
        !          2451: as:
        !          2452: .(b
        !          2453: sendmail \-bt \-Ctest.cf
        !          2454: .)b
        !          2455: which would read the configuration file
        !          2456: .q test.cf
        !          2457: and enter test mode.
        !          2458: In this mode,
        !          2459: you enter lines of the form:
        !          2460: .(b
        !          2461: rwset address
        !          2462: .)b
        !          2463: where
        !          2464: .i rwset
        !          2465: is the rewriting set you want to use
        !          2466: and
        !          2467: .i address
        !          2468: is an address to apply the set to.
        !          2469: Test mode shows you the steps it takes
        !          2470: as it proceeds,
        !          2471: finally showing you the address it ends up with.
        !          2472: You may use a comma separated list of rwsets
        !          2473: for sequential application of rules to an input;
        !          2474: ruleset three is always applied first.
        !          2475: For example:
        !          2476: .(b
        !          2477: 1,21,4 monet:bollard
        !          2478: .)b
        !          2479: first applies ruleset three to the input
        !          2480: .q monet:bollard.
        !          2481: Ruleset one is then applied to the output of ruleset three,
        !          2482: followed similarly by rulesets twenty-one and four.
        !          2483: .pp
        !          2484: If you need more detail,
        !          2485: you can also use the
        !          2486: .q \-d21
        !          2487: flag to turn on more debugging.
        !          2488: For example,
        !          2489: .(b
        !          2490: sendmail \-bt \-d21.99
        !          2491: .)b
        !          2492: turns on an incredible amount of information;
        !          2493: a single word address
        !          2494: is probably going to print out several pages worth of information.
        !          2495: .sh 3 "Building mailer descriptions"
        !          2496: .pp
        !          2497: To add an outgoing mailer to your mail system,
        !          2498: you will have to define the characteristics of the mailer.
        !          2499: .pp
        !          2500: Each mailer must have an internal name.
        !          2501: This can be arbitrary,
        !          2502: except that the names
        !          2503: .q local
        !          2504: and
        !          2505: .q prog
        !          2506: must be defined.
        !          2507: .pp
        !          2508: The pathname of the mailer must be given in the P field.
        !          2509: If this mailer should be accessed via an IPC connection,
        !          2510: use the string
        !          2511: .q [IPC]
        !          2512: instead.
        !          2513: .pp
        !          2514: The F field defines the mailer flags.
        !          2515: You should specify an
        !          2516: .q f
        !          2517: or
        !          2518: .q r
        !          2519: flag to pass the name of the sender as a
        !          2520: .b \-f
        !          2521: or
        !          2522: .b \-r
        !          2523: flag respectively.
        !          2524: These flags are only passed if they were passed to
        !          2525: .i sendmail,
        !          2526: so that mailers that give errors under some circumstances
        !          2527: can be placated.
        !          2528: If the mailer is not picky
        !          2529: you can just specify
        !          2530: .q "\-f $g"
        !          2531: in the argv template.
        !          2532: If the mailer must be called as
        !          2533: .b root
        !          2534: the
        !          2535: .q S
        !          2536: flag should be given;
        !          2537: this will not reset the userid
        !          2538: before calling the mailer\**.
        !          2539: .(f
        !          2540: \**\c
        !          2541: .i Sendmail
        !          2542: must be running setuid to root
        !          2543: for this to work.
        !          2544: .)f
        !          2545: If this mailer is local
        !          2546: (i.e., will perform final delivery
        !          2547: rather than another network hop)
        !          2548: the
        !          2549: .q l
        !          2550: flag should be given.
        !          2551: Quote characters
        !          2552: (backslashes and " marks)
        !          2553: can be stripped from addresses if the
        !          2554: .q s
        !          2555: flag is specified;
        !          2556: if this is not given
        !          2557: they are passed through.
        !          2558: If the mailer is capable of sending to more than one user
        !          2559: on the same host
        !          2560: in a single transaction
        !          2561: the
        !          2562: .q m
        !          2563: flag should be stated.
        !          2564: If this flag is on,
        !          2565: then the argv template containing
        !          2566: .b $u
        !          2567: will be repeated for each unique user
        !          2568: on a given host.
        !          2569: The
        !          2570: .q e
        !          2571: flag will mark the mailer as being
        !          2572: .q expensive,
        !          2573: which will cause
        !          2574: .i sendmail
        !          2575: to defer connection
        !          2576: until a queue run\**.
        !          2577: .(f
        !          2578: \**The
        !          2579: .q c
        !          2580: configuration option must be given
        !          2581: for this to be effective.
        !          2582: .)f
        !          2583: .pp
        !          2584: An unusual case is the
        !          2585: .q C
        !          2586: flag.
        !          2587: This flag applies to the mailer that the message is received from,
        !          2588: rather than the mailer being sent to;
        !          2589: if set,
        !          2590: the domain spec of the sender
        !          2591: (i.e., the
        !          2592: .q @host.domain
        !          2593: part)
        !          2594: is saved
        !          2595: and is appended to any addresses in the message
        !          2596: that do not already contain a domain spec.
        !          2597: For example,
        !          2598: a message of the form:
        !          2599: .(b
        !          2600: From: eric@ucbarpa
        !          2601: To: wnj@monet, mckusick
        !          2602: .)b
        !          2603: will be modified to:
        !          2604: .(b
        !          2605: From: eric@ucbarpa
        !          2606: To: wnj@monet, mckusick@ucbarpa
        !          2607: .)b
        !          2608: .i "if and only if"
        !          2609: the
        !          2610: .q C
        !          2611: flag is defined in the mailer corresponding to
        !          2612: .q eric@ucbarpa.
        !          2613: .pp
        !          2614: Other flags are described
        !          2615: in Appendix C.
        !          2616: .pp
        !          2617: The S and R fields in the mailer description
        !          2618: are per-mailer rewriting sets
        !          2619: to be applied to sender and recipient addresses
        !          2620: respectively.
        !          2621: These are applied after the sending domain is appended
        !          2622: and the general rewriting sets
        !          2623: (numbers one and two)
        !          2624: are applied,
        !          2625: but before the output rewrite
        !          2626: (ruleset four)
        !          2627: is applied.
        !          2628: A typical use is to append the current domain
        !          2629: to addresses that do not already have a domain.
        !          2630: For example,
        !          2631: a header of the form:
        !          2632: .(b
        !          2633: From: eric
        !          2634: .)b
        !          2635: might be changed to be:
        !          2636: .(b
        !          2637: From: eric@ucbarpa
        !          2638: .)b
        !          2639: or
        !          2640: .(b
        !          2641: From: ucbvax!eric
        !          2642: .)b
        !          2643: depending on the domain it is being shipped into.
        !          2644: These sets can also be used
        !          2645: to do special purpose output rewriting
        !          2646: in cooperation with ruleset four.
        !          2647: .pp
        !          2648: The E field defines the string to use
        !          2649: as an end-of-line indication.
        !          2650: A string containing only newline is the default.
        !          2651: The usual backslash escapes
        !          2652: (\er, \en, \ef, \eb)
        !          2653: may be used.
        !          2654: .pp
        !          2655: Finally,
        !          2656: an argv template is given as the E field.
        !          2657: It may have embedded spaces.
        !          2658: If there is no argv with a
        !          2659: .b $u
        !          2660: macro in it,
        !          2661: .i sendmail
        !          2662: will speak SMTP
        !          2663: to the mailer.
        !          2664: If the pathname for this mailer is
        !          2665: .q [IPC],
        !          2666: the argv should be
        !          2667: .(b
        !          2668: IPC $h [ \fIport\fP ]
        !          2669: .)b
        !          2670: where
        !          2671: .i port
        !          2672: is the optional port number
        !          2673: to connect to.
        !          2674: .pp
        !          2675: For example,
        !          2676: the specifications:
        !          2677: .(b
        !          2678: .ta \w'Mlocal, 'u +\w'P=/bin/mail, 'u +\w'F=rlsm, 'u +\w'S=10, 'u +\w'R=20, 'u
        !          2679: Mlocal,        P=/bin/mail,    F=rlsm  S=10,   R=20,   A=mail \-d $u
        !          2680: Mether,        P=[IPC],        F=meC,  S=11,   R=21,   A=IPC $h, M=100000
        !          2681: .)b
        !          2682: specifies a mailer to do local delivery
        !          2683: and a mailer for ethernet delivery.
        !          2684: The first is called
        !          2685: .q local,
        !          2686: is located in the file
        !          2687: .q /bin/mail,
        !          2688: takes a picky
        !          2689: .b \-r
        !          2690: flag,
        !          2691: does local delivery,
        !          2692: quotes should be stripped from addresses,
        !          2693: and multiple users can be delivered at once;
        !          2694: ruleset ten
        !          2695: should be applied to sender addresses in the message
        !          2696: and ruleset twenty
        !          2697: should be applied to recipient addresses;
        !          2698: the argv to send to a message will be the word
        !          2699: .q mail,
        !          2700: the word
        !          2701: .q \-d,
        !          2702: and words containing the name of the receiving user.
        !          2703: If a
        !          2704: .b \-r
        !          2705: flag is inserted
        !          2706: it will be between the words
        !          2707: .q mail
        !          2708: and
        !          2709: .q \-d.
        !          2710: The second mailer is called
        !          2711: .q ether,
        !          2712: it should be connected to via an IPC connection,
        !          2713: it can handle multiple users at once,
        !          2714: connections should be deferred,
        !          2715: and any domain from the sender address
        !          2716: should be appended to any receiver name
        !          2717: without a domain;
        !          2718: sender addresses should be processed by ruleset eleven
        !          2719: and recipient addresses by ruleset twenty-one.
        !          2720: There is a 100,000 byte limit on messages passed through this mailer.
        !          2721: .++ A
        !          2722: .+c "COMMAND LINE FLAGS"
        !          2723: .ba 0
        !          2724: .nr ii 1i
        !          2725: .pp
        !          2726: Arguments must be presented with flags before addresses.
        !          2727: The flags are:
        !          2728: .ip "\-f\ \fIaddr\fP"
        !          2729: The sender's machine address is
        !          2730: .i addr .
        !          2731: This flag is ignored unless the real user
        !          2732: is listed as a
        !          2733: .q "trusted user"
        !          2734: or if
        !          2735: .i addr
        !          2736: contains an exclamation point
        !          2737: (because of certain restrictions in UUCP).
        !          2738: .ip "\-r\ \fIaddr\fP"
        !          2739: An obsolete form of
        !          2740: .b \-f .
        !          2741: .ip "\-h\ \fIcnt\fP"
        !          2742: Sets the
        !          2743: .q "hop count"
        !          2744: to
        !          2745: .i cnt .
        !          2746: This represents the number of times this message has been processed
        !          2747: by
        !          2748: .i sendmail
        !          2749: (to the extent that it is supported by the underlying networks).
        !          2750: .i Cnt
        !          2751: is incremented during processing,
        !          2752: and if it reaches
        !          2753: MAXHOP
        !          2754: (currently 30)
        !          2755: .i sendmail
        !          2756: throws away the message with an error.
        !          2757: .ip \-F\fIname\fP
        !          2758: Sets the full name of this user to
        !          2759: .i name .
        !          2760: .ip \-n
        !          2761: Don't do aliasing or forwarding.
        !          2762: .ip \-t
        !          2763: Read the header for
        !          2764: .q To: ,
        !          2765: .q Cc: ,
        !          2766: and
        !          2767: .q Bcc:
        !          2768: lines, and send to everyone listed in those lists.
        !          2769: The
        !          2770: .q Bcc:
        !          2771: line will be deleted before sending.
        !          2772: Any addresses in the argument vector will be deleted
        !          2773: from the send list.
        !          2774: .ip \-b\fIx\fP
        !          2775: Set operation mode to
        !          2776: .i x .
        !          2777: Operation modes are:
        !          2778: .(b
        !          2779: .ta 4n
        !          2780: m      Deliver mail (default)
        !          2781: a      Run in arpanet mode (see below)
        !          2782: s      Speak SMTP on input side
        !          2783: d      Run as a daemon
        !          2784: t      Run in test mode
        !          2785: v      Just verify addresses, don't collect or deliver
        !          2786: i      Initialize the alias database
        !          2787: p      Print the mail queue
        !          2788: z      Freeze the configuration file
        !          2789: .)b
        !          2790: The special processing for the
        !          2791: ARPANET
        !          2792: includes reading the
        !          2793: .q "From:"
        !          2794: line from the header to find the sender,
        !          2795: printing
        !          2796: ARPANET
        !          2797: style messages
        !          2798: (preceded by three digit reply codes for compatibility with
        !          2799: the FTP protocol
        !          2800: [Neigus73, Postel74, Postel77]),
        !          2801: and ending lines of error messages with <CRLF>.
        !          2802: .ip \-q\fItime\fP
        !          2803: Try to process the queued up mail.
        !          2804: If the time is given,
        !          2805: a sendmail will run through the queue at the specified interval
        !          2806: to deliver queued mail;
        !          2807: otherwise, it only runs once.
        !          2808: .ip \-C\fIfile\fP
        !          2809: Use a different configuration file.
        !          2810: .ip \-d\fIlevel\fP
        !          2811: Set debugging level.
        !          2812: .ip \-o\fIx\|value\fP
        !          2813: Set option
        !          2814: .i x
        !          2815: to the specified
        !          2816: .i value .
        !          2817: These options are described in Appendix B.
        !          2818: .pp
        !          2819: There are a number of options that may be specified as
        !          2820: primitive flags
        !          2821: (provided for compatibility with
        !          2822: .i delivermail ).
        !          2823: These are the e, i, m, and v options.
        !          2824: Also,
        !          2825: the f option
        !          2826: may be specified as the
        !          2827: .b \-s
        !          2828: flag.
        !          2829: .+c "CONFIGURATION OPTIONS"
        !          2830: .pp
        !          2831: The following options may be set using the
        !          2832: .b \-o
        !          2833: flag on the command line
        !          2834: or the
        !          2835: .b O
        !          2836: line in the configuration file:
        !          2837: .nr ii 1i
        !          2838: .ip A\fIfile\fP
        !          2839: Use the named
        !          2840: .i file
        !          2841: as the alias file.
        !          2842: If no file is specified,
        !          2843: use
        !          2844: .i aliases
        !          2845: in the current directory.
        !          2846: .ip a
        !          2847: If set,
        !          2848: wait for an
        !          2849: .q @:@
        !          2850: entry to exist in the alias database
        !          2851: before starting up.
        !          2852: If it does not appear in five minutes,
        !          2853: rebuild the database.
        !          2854: .ip c
        !          2855: If an outgoing mailer is marked as being expensive,
        !          2856: don't connect immediately.
        !          2857: This requires that queueing be compiled in,
        !          2858: since it will depend on a queue run process to
        !          2859: actually send the mail.
        !          2860: .ip d\fIx\fP
        !          2861: Deliver in mode
        !          2862: .i x .
        !          2863: Legal modes are:
        !          2864: .(b
        !          2865: .ta 4n
        !          2866: i      Deliver interactively (synchronously)
        !          2867: b      Deliver in background (asynchronously)
        !          2868: q      Just queue the message (deliver during queue run)
        !          2869: .)b
        !          2870: .ip D
        !          2871: If set,
        !          2872: rebuild the alias database if necessary and possible.
        !          2873: If this option is not set,
        !          2874: .i sendmail
        !          2875: will never rebuild the alias database
        !          2876: unless explicitly requested
        !          2877: using
        !          2878: .b \-bi .
        !          2879: .ip e\fIx\fP
        !          2880: Dispose of errors using mode
        !          2881: .i x .
        !          2882: The values for
        !          2883: .i x
        !          2884: are:
        !          2885: .(b
        !          2886: p      Print error messages (default)
        !          2887: q      No messages, just give exit status
        !          2888: m      Mail back errors
        !          2889: w      Write back errors (mail if user not logged in)
        !          2890: e      Mail back errors and give zero exit stat always
        !          2891: .)b
        !          2892: .ip F\fIn\fP
        !          2893: The temporary file mode,
        !          2894: in octal.
        !          2895: 644 and 600 are good choices.
        !          2896: .ip f
        !          2897: Save
        !          2898: Unix-style
        !          2899: .q From
        !          2900: lines at the front of headers.
        !          2901: Normally they are assumed redundant
        !          2902: and discarded.
        !          2903: .ip g\fIn\fP
        !          2904: Set the default group id
        !          2905: for mailers to run in
        !          2906: to
        !          2907: .i n .
        !          2908: .ip H\fIfile\fP
        !          2909: Specify the help file
        !          2910: for SMTP.
        !          2911: .ip i
        !          2912: Ignore dots in incoming messages.
        !          2913: .ip L\fIn\fP
        !          2914: Set the default log level to
        !          2915: .i n .
        !          2916: .ip M\fIx\|value\fP
        !          2917: Set the macro
        !          2918: .i x
        !          2919: to
        !          2920: .i value .
        !          2921: This is intended only for use from the command line.
        !          2922: .ip m
        !          2923: Send to me too,
        !          2924: even if I am in an alias expansion.
        !          2925: .ip o
        !          2926: Assume that the headers may be in old format,
        !          2927: i.e.,
        !          2928: spaces delimit names.
        !          2929: This actually turns on
        !          2930: an adaptive algorithm:
        !          2931: if any recipient address contains a comma, parenthesis,
        !          2932: or angle bracket,
        !          2933: it will be assumed that commas already exist.
        !          2934: If this flag is not on,
        !          2935: only commas delimit names.
        !          2936: Headers are always output with commas between the names.
        !          2937: .ip Q\fIdir\fP
        !          2938: Use the named
        !          2939: .i dir
        !          2940: as the queue directory.
        !          2941: .ip r\fItime\fP
        !          2942: Timeout reads after
        !          2943: .i time
        !          2944: interval.
        !          2945: .ip S\fIfile\fP
        !          2946: Log statistics in the named
        !          2947: .i file .
        !          2948: .ip s
        !          2949: Be super-safe when running things,
        !          2950: i.e.,
        !          2951: always instantiate the queue file,
        !          2952: even if you are going to attempt immediate delivery.
        !          2953: .i Sendmail
        !          2954: always instantiates the queue file
        !          2955: before returning control the the client
        !          2956: under any circumstances.
        !          2957: .ip T\fItime\fP
        !          2958: Set the queue timeout to
        !          2959: .i time .
        !          2960: After this interval,
        !          2961: messages that have not been successfully sent
        !          2962: will be returned to the sender.
        !          2963: .ip t\fIS,D\fP
        !          2964: Set the local timezone name to
        !          2965: .i S
        !          2966: for standard time and
        !          2967: .i D
        !          2968: for daylight time;
        !          2969: this is only used under version six.
        !          2970: .ip u\fIn\fP
        !          2971: Set the default userid for mailers to
        !          2972: .i n .
        !          2973: Mailers without the
        !          2974: .i S
        !          2975: flag in the mailer definition
        !          2976: will run as this user.
        !          2977: .ip v
        !          2978: Run in verbose mode.
        !          2979: .+c "MAILER FLAGS"
        !          2980: The following flags may be set in the mailer description.
        !          2981: .nr ii 4n
        !          2982: .ip f
        !          2983: The mailer wants a
        !          2984: .b \-f
        !          2985: .i from
        !          2986: flag,
        !          2987: but only if this is a network forward operation
        !          2988: (i.e.,
        !          2989: the mailer will give an error
        !          2990: if the executing user
        !          2991: does not have special permissions).
        !          2992: .ip r
        !          2993: Same as
        !          2994: .b f ,
        !          2995: but sends a
        !          2996: .b \-r
        !          2997: flag.
        !          2998: .ip S
        !          2999: Don't reset the userid
        !          3000: before calling the mailer.
        !          3001: This would be used in a secure environment
        !          3002: where
        !          3003: .i sendmail
        !          3004: ran as root.
        !          3005: This could be used to avoid forged addresses.
        !          3006: This flag is suppressed if given from an
        !          3007: .q unsafe
        !          3008: environment
        !          3009: (e.g, a user's mail.cf file).
        !          3010: .ip n
        !          3011: Do not insert a UNIX-style
        !          3012: .q From
        !          3013: line on the front of the message.
        !          3014: .ip l
        !          3015: This mailer is local
        !          3016: (i.e.,
        !          3017: final delivery will be performed).
        !          3018: .ip s
        !          3019: Strip quote characters off of the address
        !          3020: before calling the mailer.
        !          3021: .ip m
        !          3022: This mailer can send to multiple users
        !          3023: on the same host
        !          3024: in one transaction.
        !          3025: When a
        !          3026: .b $u
        !          3027: macro occurs in the
        !          3028: .i argv
        !          3029: part of the mailer definition,
        !          3030: that field will be repeated as necessary
        !          3031: for all qualifying users.
        !          3032: .ip F
        !          3033: This mailer wants a
        !          3034: .q From:
        !          3035: header line.
        !          3036: .ip D
        !          3037: This mailer wants a
        !          3038: .q Date:
        !          3039: header line.
        !          3040: .ip M
        !          3041: This mailer wants a
        !          3042: .q Message-Id:
        !          3043: header line.
        !          3044: .ip x
        !          3045: This mailer wants a
        !          3046: .q Full-Name:
        !          3047: header line.
        !          3048: .ip P
        !          3049: This mailer wants a
        !          3050: .q Return-Path:
        !          3051: line.
        !          3052: .ip u
        !          3053: Upper case should be preserved in user names
        !          3054: for this mailer.
        !          3055: .ip h
        !          3056: Upper case should be preserved in host names
        !          3057: for this mailer.
        !          3058: .ip A
        !          3059: This is an Arpanet-compatible mailer,
        !          3060: and all appropriate modes should be set.
        !          3061: .ip U
        !          3062: This mailer wants Unix-style
        !          3063: .q From
        !          3064: lines with the ugly UUCP-style
        !          3065: .q "remote from <host>"
        !          3066: on the end.
        !          3067: .ip e
        !          3068: This mailer is expensive to connect to,
        !          3069: so try to avoid connecting normally;
        !          3070: any necessary connection will occur during a queue run.
        !          3071: .ip X
        !          3072: This mailer want to use the hidden dot algorithm
        !          3073: as specified in RFC821;
        !          3074: basically,
        !          3075: any line beginning with a dot
        !          3076: will have an extra dot prepended
        !          3077: (to be stripped at the other end).
        !          3078: This insures that lines in the message containing a dot
        !          3079: will not terminate the message prematurely.
        !          3080: .ip L
        !          3081: Limit the line lengths as specified in RFC821.
        !          3082: .ip P
        !          3083: Use the return-path in the SMTP
        !          3084: .q "MAIL FROM:"
        !          3085: command
        !          3086: rather than just the return address;
        !          3087: although this is required in RFC821,
        !          3088: many hosts do not process return paths properly.
        !          3089: .ip I
        !          3090: This mailer will be speaking SMTP
        !          3091: to another
        !          3092: .i sendmail
        !          3093: \*-
        !          3094: as such it can use special protocol features.
        !          3095: This option is not required
        !          3096: (i.e.,
        !          3097: if this option is omitted the transmission will still operate successfully,
        !          3098: although perhaps not as efficiently as possible).
        !          3099: .ip C
        !          3100: If mail is
        !          3101: .i received
        !          3102: from a mailer with this flag set,
        !          3103: any addresses in the header that do not have an at sign
        !          3104: (\c
        !          3105: .q @ )
        !          3106: after being rewritten by ruleset three
        !          3107: will have the
        !          3108: .q @domain
        !          3109: clause from the sender
        !          3110: tacked on.
        !          3111: This allows mail with headers of the form:
        !          3112: .(b
        !          3113: From: usera@hosta
        !          3114: To: userb@hostb, userc
        !          3115: .)b
        !          3116: to be rewritten as:
        !          3117: .(b
        !          3118: From: usera@hosta
        !          3119: To: userb@hostb, userc@hosta
        !          3120: .)b
        !          3121: automatically.
        !          3122: .+c "OTHER CONFIGURATION"
        !          3123: .rm $0
        !          3124: .nr ii 1i
        !          3125: .pp
        !          3126: There are some configuration changes that can be made by
        !          3127: recompiling
        !          3128: .i sendmail .
        !          3129: These are located in three places:
        !          3130: .ip md/config.m4
        !          3131: These contain operating-system dependent descriptions.
        !          3132: They are interpolated into the Makefiles in the
        !          3133: .i src
        !          3134: and
        !          3135: .i aux
        !          3136: directories.
        !          3137: This includes information about what version of UNIX
        !          3138: you are running,
        !          3139: what libraries you have to include, etc.
        !          3140: .ip src/conf.h
        !          3141: Configuration parameters that may be tweaked by the installer
        !          3142: are included in conf.h.
        !          3143: .ip src/conf.c
        !          3144: Some special routines and a few variables
        !          3145: may be defined in conf.c.
        !          3146: For the most part these are selected from the settings
        !          3147: in conf.h.
        !          3148: .uh "Parameters in md/config.m4"
        !          3149: .pp
        !          3150: The following compilation flags may be defined in the
        !          3151: .i m4CONFIG
        !          3152: macro in
        !          3153: .i md/config.m4
        !          3154: to define the environment in which you are operating.
        !          3155: .ip V6
        !          3156: If set,
        !          3157: this will compile a version 6 system,
        !          3158: with 8-bit user id's,
        !          3159: single character tty id's,
        !          3160: etc.
        !          3161: .ip VMUNIX
        !          3162: If set,
        !          3163: you will be assumed to have a Berkeley 4BSD or 4.1BSD,
        !          3164: including the
        !          3165: .i vfork \|(2)
        !          3166: system call,
        !          3167: special types defined in <sys/types.h>
        !          3168: (e.g, u_char),
        !          3169: etc.
        !          3170: .lp
        !          3171: If none of these flags are set,
        !          3172: a version 7 system is assumed.
        !          3173: .pp
        !          3174: You will also have to specify what libraries to link with
        !          3175: .i sendmail
        !          3176: in the
        !          3177: .i m4LIBS
        !          3178: macro.
        !          3179: Most notably, you will have to include
        !          3180: .B \-ljobs
        !          3181: if you are running a 4.1BSD system.
        !          3182: .uh "Parameters in src/conf.h"
        !          3183: .pp
        !          3184: Parameters and compilation options
        !          3185: are defined in conf.h.
        !          3186: Most of these need not normally be tweaked;
        !          3187: common parameters are all in sendmail.cf.
        !          3188: However, the sizes of certain primitive vectors, etc.,
        !          3189: are included in this file.
        !          3190: The numbers following the parameters
        !          3191: are their default value.
        !          3192: .nr ii 1.2i
        !          3193: .ip "MAXLINE [256]"
        !          3194: The maximum line length of any input line.
        !          3195: If message lines exceed this length
        !          3196: they will still be processed correctly;
        !          3197: however, header lines,
        !          3198: configuration file lines,
        !          3199: alias lines,
        !          3200: etc.,
        !          3201: must fit within this limit.
        !          3202: .ip "MAXNAME [128]"
        !          3203: The maximum length of any name,
        !          3204: such as a host or a user name.
        !          3205: .ip "MAXFIELD [2500]"
        !          3206: The maximum total length of any header field,
        !          3207: including continuation lines.
        !          3208: .ip "MAXPV [40]"
        !          3209: The maximum number of parameters to any mailer.
        !          3210: This limits the number of recipients that may be passed in one transaction.
        !          3211: .ip "MAXHOP [30]"
        !          3212: When a message has been processed more than this number of times,
        !          3213: sendmail rejects the message
        !          3214: on the assumption that there has been an aliasing loop.
        !          3215: This can be determined from the
        !          3216: .b \-h
        !          3217: flag
        !          3218: or by counting the number of trace fields
        !          3219: (i.e,
        !          3220: .q Received:
        !          3221: lines)
        !          3222: in the message header.
        !          3223: .ip "MAXATOM [100]"
        !          3224: The maximum number of atoms
        !          3225: (tokens)
        !          3226: in a single address.
        !          3227: For example,
        !          3228: the address
        !          3229: .q "eric@Berkeley"
        !          3230: is three atoms.
        !          3231: .ip "MAXMAILERS [25]"
        !          3232: The maximum number of mailers that may be defined
        !          3233: in the configuration file.
        !          3234: .ip "MAXRWSETS [30]"
        !          3235: The maximum number of rewriting sets
        !          3236: that may be defined.
        !          3237: .ip "MAXPRIORITIES [25]"
        !          3238: The maximum number of values for the
        !          3239: .q Precedence:
        !          3240: field that may be defined
        !          3241: (using the
        !          3242: .b P
        !          3243: line in sendmail.cf).
        !          3244: .ip "MAXTRUST [30]"
        !          3245: The maximum number of trusted users that may be defined
        !          3246: (using the
        !          3247: .b T
        !          3248: line in sendmail.cf).
        !          3249: .lp
        !          3250: A number of other compilation options exist.
        !          3251: These specify whether or not specific code should be compiled in.
        !          3252: .nr ii 1i
        !          3253: .ip DBM
        !          3254: If set,
        !          3255: the
        !          3256: .q DBM
        !          3257: package in UNIX is used
        !          3258: (see DBM(3X) in [UNIX80]).
        !          3259: If not set,
        !          3260: a much less efficient algorithm for processing aliases is used.
        !          3261: .ip DEBUG
        !          3262: If set, debugging information is compiled in.
        !          3263: To actually get the debugging output,
        !          3264: the
        !          3265: .b \-d
        !          3266: flag must be used.
        !          3267: .ip LOG
        !          3268: If set,
        !          3269: the
        !          3270: .i syslog
        !          3271: routine in use at some sites is used.
        !          3272: This makes an informational log record
        !          3273: for each message processed,
        !          3274: and makes a higher priority log record
        !          3275: for internal system errors.
        !          3276: .ip QUEUE
        !          3277: This flag should be set to compile in the queueing code.
        !          3278: If this is not set,
        !          3279: mailers must accept the mail immediately
        !          3280: or it will be returned to the sender.
        !          3281: .ip SMTP
        !          3282: If set,
        !          3283: the code to handle user and server SMTP will be compiled in.
        !          3284: This is only necessary if your machine has some mailer
        !          3285: that speaks SMTP.
        !          3286: .ip DAEMON
        !          3287: If set,
        !          3288: code to run a daemon is compiled in.
        !          3289: This code is for 4.2BSD
        !          3290: if the
        !          3291: NVMUNIX
        !          3292: flag is specified;
        !          3293: otherwise,
        !          3294: 4.1a BSD code is used.
        !          3295: Beware however
        !          3296: that there are bugs in the 4.1a code
        !          3297: that make it impossible for
        !          3298: .b sendmail
        !          3299: to work correctly
        !          3300: under heavy load.
        !          3301: .ip UGLYUUCP
        !          3302: If you have a UUCP host adjacent to you which is not running
        !          3303: a reasonable version of
        !          3304: .i rmail ,
        !          3305: you will have to set this flag to include the
        !          3306: .q "remote from sysname"
        !          3307: info on the from line.
        !          3308: Otherwise, UUCP gets confused about where the mail came from.
        !          3309: .ip NOTUNIX
        !          3310: If you are using a non-UNIX mail format,
        !          3311: you can set this flag to turn off special processing
        !          3312: of UNIX-style
        !          3313: .q "From "
        !          3314: lines.
        !          3315: .uh "Configuration in src/conf.c"
        !          3316: .pp
        !          3317: Not all header semantics are defined in the configuration file.
        !          3318: Header lines that should only be included by certain mailers
        !          3319: (as well as other more obscure semantics)
        !          3320: must be specified in the
        !          3321: .i HdrInfo
        !          3322: table in
        !          3323: .i conf.c .
        !          3324: This table contains the header name
        !          3325: (which should be in all lower case)
        !          3326: and a set of header control flags (described below),
        !          3327: The flags are:
        !          3328: .ip H_ACHECK
        !          3329: Normally when the check is made to see if a header line is compatible
        !          3330: with a mailer,
        !          3331: .i sendmail
        !          3332: will not delete an existing line.
        !          3333: If this flag is set,
        !          3334: .i sendmail
        !          3335: will delete
        !          3336: even existing header lines.
        !          3337: That is,
        !          3338: if this bit is set and the mailer does not have flag bits set
        !          3339: that intersect with the required mailer flags
        !          3340: in the header definition in
        !          3341: sendmail.cf,
        !          3342: the header line is
        !          3343: .i always
        !          3344: deleted.
        !          3345: .ip H_EOH
        !          3346: If this header field is set,
        !          3347: treat it like a blank line,
        !          3348: i.e.,
        !          3349: it will signal the end of the header
        !          3350: and the beginning of the message text.
        !          3351: .ip H_FORCE
        !          3352: Add this header entry
        !          3353: even if one existed in the message before.
        !          3354: If a header entry does not have this bit set,
        !          3355: .i sendmail
        !          3356: will not add another header line if a header line
        !          3357: of this name already existed.
        !          3358: This would normally be used to stamp the message
        !          3359: by everyone who handled it.
        !          3360: .ip H_TRACE
        !          3361: If set,
        !          3362: this is a timestamp
        !          3363: (trace)
        !          3364: field.
        !          3365: If the number of trace fields in a message
        !          3366: exceeds a preset amount
        !          3367: the message is returned
        !          3368: on the assumption that it has an aliasing loop.
        !          3369: .ip H_RCPT
        !          3370: If set,
        !          3371: this field contains recipient addresses.
        !          3372: This is used by the
        !          3373: .b \-t
        !          3374: flag to determine who to send to
        !          3375: when it is collecting recipients from the message.
        !          3376: .ip H_FROM
        !          3377: This flag indicates that this field
        !          3378: specifies a sender.
        !          3379: The order of these fields in the
        !          3380: .i HdrInfo
        !          3381: table specifies
        !          3382: .i sendmail's
        !          3383: preference
        !          3384: for which field to return error messages to.
        !          3385: .nr ii 5n
        !          3386: .lp
        !          3387: Let's look at a sample
        !          3388: .i HdrInfo
        !          3389: specification:
        !          3390: .(b
        !          3391: .ta 4n +\w'"return-receipt-to",  'u
        !          3392: struct hdrinfo HdrInfo[] =
        !          3393: {
        !          3394:             /* originator fields, most to least significant  */
        !          3395:        "resent-sender",        H_FROM,
        !          3396:        "resent-from",  H_FROM,
        !          3397:        "sender",       H_FROM,
        !          3398:        "from", H_FROM,
        !          3399:        "full-name",    H_ACHECK,
        !          3400:             /* destination fields */
        !          3401:        "to",   H_RCPT,
        !          3402:        "resent-to",    H_RCPT,
        !          3403:        "cc",   H_RCPT,
        !          3404:             /* message identification and control */
        !          3405:        "message",      H_EOH,
        !          3406:        "text", H_EOH,
        !          3407:             /* trace fields */
        !          3408:        "received",     H_TRACE|H_FORCE,
        !          3409: 
        !          3410:        NULL,   0,
        !          3411: };
        !          3412: .)b
        !          3413: This structure indicates that the
        !          3414: .q To: ,
        !          3415: .q Resent-To: ,
        !          3416: and
        !          3417: .q Cc:
        !          3418: fields
        !          3419: all specify recipient addresses.
        !          3420: Any
        !          3421: .q Full-Name:
        !          3422: field will be deleted unless the required mailer flag
        !          3423: (indicated in the configuration file)
        !          3424: is specified.
        !          3425: The
        !          3426: .q Message:
        !          3427: and
        !          3428: .q Text:
        !          3429: fields will terminate the header;
        !          3430: these are specified in new protocols
        !          3431: [NBS80]
        !          3432: or used by random dissenters around the network world.
        !          3433: The
        !          3434: .q Received:
        !          3435: field will always be added,
        !          3436: and can be used to trace messages.
        !          3437: .pp
        !          3438: There are a number of important points here.
        !          3439: First,
        !          3440: header fields are not added automatically just because they are in the
        !          3441: .i HdrInfo
        !          3442: structure;
        !          3443: they must be specified in the configuration file
        !          3444: in order to be added to the message.
        !          3445: Any header fields mentioned in the configuration file but not
        !          3446: mentioned in the
        !          3447: .i HdrInfo
        !          3448: structure have default processing performed;
        !          3449: that is,
        !          3450: they are added unless they were in the message already.
        !          3451: Second,
        !          3452: the
        !          3453: .i HdrInfo
        !          3454: structure only specifies cliched processing;
        !          3455: certain headers are processed specially by ad hoc code
        !          3456: regardless of the status specified in
        !          3457: .i HdrInfo .
        !          3458: For example,
        !          3459: the
        !          3460: .q Sender:
        !          3461: and
        !          3462: .q From:
        !          3463: fields are always scanned on ARPANET mail
        !          3464: to determine the sender;
        !          3465: this is used to perform the
        !          3466: .q "return to sender"
        !          3467: function.
        !          3468: The
        !          3469: .q "From:"
        !          3470: and
        !          3471: .q "Full-Name:"
        !          3472: fields are used to determine the full name of the sender
        !          3473: if possible;
        !          3474: this is stored in the macro
        !          3475: .b $x
        !          3476: and used in a number of ways.
        !          3477: .pp
        !          3478: The file
        !          3479: .i conf.c
        !          3480: also contains the specification of ARPANET reply codes.
        !          3481: There are four classifications these fall into:
        !          3482: .(b
        !          3483: .sz -1
        !          3484: .ta \w'char  'u +\w'Arpa_TUsrerr[] =  'u +\w'"888";  'u
        !          3485: char   Arpa_Info[] =   "050";  /* arbitrary info */
        !          3486: char   Arpa_TSyserr[] =        "455";  /* some (transient) system error */
        !          3487: char   Arpa_PSyserr[] =        "554";  /* some (transient) system error */
        !          3488: char   Arpa_Usrerr[] = "554";  /* some (fatal) user error */
        !          3489: .sz
        !          3490: .)b
        !          3491: The class
        !          3492: .i Arpa_Info
        !          3493: is for any information that is not required by the protocol,
        !          3494: such as forwarding information.
        !          3495: .i Arpa_TSyserr
        !          3496: and
        !          3497: .i Arpa_PSyserr
        !          3498: is printed by the
        !          3499: .i syserr
        !          3500: routine.
        !          3501: TSyserr
        !          3502: is printed out for transient errors,
        !          3503: whereas PSyserr
        !          3504: is printed for permanent errors;
        !          3505: the distinction is made based on the value of
        !          3506: .i errno .
        !          3507: Finally,
        !          3508: .i Arpa_Usrerr
        !          3509: is the result of a user error
        !          3510: and is generated by the
        !          3511: .i usrerr
        !          3512: routine;
        !          3513: these are generated when the user has specified something wrong,
        !          3514: and hence the error is permanent,
        !          3515: i.e.,
        !          3516: it will not work simply by resubmitting the request.
        !          3517: .pp
        !          3518: If it is necessary to restrict mail through a relay,
        !          3519: the
        !          3520: .i checkcompat
        !          3521: routine can be modified.
        !          3522: This routine is called for every recipient address.
        !          3523: It can return
        !          3524: .b TRUE
        !          3525: to indicate that the address is acceptable
        !          3526: and mail processing will continue,
        !          3527: or it can return
        !          3528: .b FALSE
        !          3529: to reject the recipient.
        !          3530: If it returns false,
        !          3531: it is up to
        !          3532: .i checkcompat
        !          3533: to print an error message
        !          3534: (using
        !          3535: .i usrerr )
        !          3536: saying why the message is rejected.
        !          3537: For example,
        !          3538: .i checkcompat
        !          3539: could read:
        !          3540: .(b
        !          3541: .re
        !          3542: .sz -1
        !          3543: .ta 4n +4n +4n +4n +4n +4n +4n
        !          3544: bool
        !          3545: checkcompat(to)
        !          3546:        register ADDRESS *to;
        !          3547: {
        !          3548:        if (MsgSize > 50000 && to->q_mailer != LocalMailer)
        !          3549:        {
        !          3550:                usrerr("Message too large for non-local delivery");
        !          3551:                NoReturn = TRUE;
        !          3552:                return (FALSE);
        !          3553:        }
        !          3554:        return (TRUE);
        !          3555: }
        !          3556: .sz
        !          3557: .)b
        !          3558: This would reject messages greater than 50000 bytes
        !          3559: unless they were local.
        !          3560: The
        !          3561: .i NoReturn
        !          3562: flag can be sent to supress the return of the actual body
        !          3563: of the message in the error return.
        !          3564: The actual use of this routine is highly dependent on the
        !          3565: implementation,
        !          3566: and use should be limited.
        !          3567: .+c "SUMMARY OF SUPPORT FILES"
        !          3568: .pp
        !          3569: This is a summary of the support files
        !          3570: that
        !          3571: .i sendmail
        !          3572: creates or generates.
        !          3573: .nr ii 1i
        !          3574: .ip "/usr/lib/sendmail"
        !          3575: The binary of
        !          3576: .i sendmail .
        !          3577: .ip /usr/bin/newaliases
        !          3578: A link to /usr/lib/sendmail;
        !          3579: causes the alias database to be rebuilt.
        !          3580: Running this program is completely equivalent to giving
        !          3581: .i sendmail
        !          3582: the
        !          3583: .b \-bi
        !          3584: flag.
        !          3585: .ip /usr/bin/mailq
        !          3586: Prints a listing of the mail queue.
        !          3587: This program is equivalent to using the
        !          3588: .b \-bp
        !          3589: flag to
        !          3590: .i sendmail .
        !          3591: .ip /usr/lib/sendmail.cf
        !          3592: The configuration file,
        !          3593: in textual form.
        !          3594: .ip /usr/lib/sendmail.fc
        !          3595: The configuration file
        !          3596: represented as a memory image.
        !          3597: .ip /usr/lib/sendmail.hf
        !          3598: The SMTP help file.
        !          3599: .ip /usr/lib/sendmail.st
        !          3600: A statistics file; need not be present.
        !          3601: .ip /usr/lib/aliases
        !          3602: The textual version of the alias file.
        !          3603: .ip /usr/lib/aliases.{pag,dir}
        !          3604: The alias file in
        !          3605: .i dbm \|(3)
        !          3606: format.
        !          3607: .ip /etc/syslog
        !          3608: The program to do logging.
        !          3609: .ip /etc/syslog.conf
        !          3610: The configuration file for syslog.
        !          3611: .ip /etc/syslog.pid
        !          3612: Contains the process id of the currently running syslog.
        !          3613: .ip /usr/spool/mqueue
        !          3614: The directory in which the mail queue
        !          3615: and temporary files reside.
        !          3616: .ip /usr/spool/mqueue/qf*
        !          3617: Control (queue) files for messages.
        !          3618: .ip /usr/spool/mqueue/df*
        !          3619: Data files.
        !          3620: .ip /usr/spool/mqueue/lf*
        !          3621: Lock files
        !          3622: .ip /usr/spool/mqueue/tf*
        !          3623: Temporary versions of the qf files,
        !          3624: used during queue file rebuild.
        !          3625: .ip /usr/spool/mqueue/nf*
        !          3626: A file used when creating a unique id.
        !          3627: .ip /usr/spool/mqueue/xf*
        !          3628: A transcript of the current session.
        !          3629: .ro
        !          3630: .ls 1
        !          3631: .tp
        !          3632: .sp 2i
        !          3633: .in 0
        !          3634: .ce 100
        !          3635: .sz 24
        !          3636: .b SENDMAIL
        !          3637: .sz 14
        !          3638: .sp
        !          3639: INSTALLATION AND OPERATION GUIDE
        !          3640: .sp
        !          3641: .sz 10
        !          3642: Eric Allman
        !          3643: Britton-Lee, Inc.
        !          3644: .sp
        !          3645: Version 4.2
        !          3646: .ce 0
        !          3647: .bp 1
        !          3648: .ce
        !          3649: .sz 12
        !          3650: TABLE OF CONTENTS
        !          3651: .sz 10
        !          3652: .sp 2
        !          3653: .\" remove some things to avoid "out of temp file space" problem
        !          3654: .rm sh
        !          3655: .rm (x
        !          3656: .rm )x
        !          3657: .rm ip
        !          3658: .rm pp
        !          3659: .rm lp
        !          3660: .rm he
        !          3661: .rm fo
        !          3662: .rm eh
        !          3663: .rm oh
        !          3664: .rm ef
        !          3665: .rm of
        !          3666: .xp

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.