sendmail(8)

Name

sendmail, newaliases, mailq − send mail over the internet

Syntax

/usr/lib/sendmail [ flags ] [ address ... ]

newaliases

mailq

Description

The sendmail command sends a message to one or more people, routing the message over whatever networks are necessary. The sendmail command does internetwork forwarding as necessary to deliver the message to the correct place.

The sendmail command is not intended as a user interface routine. Other programs provide user-friendly front ends, while sendmail is used only to deliver pre-formatted messages.

With no flags, sendmail reads its standard input up to a CTRL/D or a line with a single dot and sends a copy of the letter found there to all of the addresses listed. It determines the network to use based on the syntax and contents of the addresses.

Local addresses are looked up in a file and aliased appropriately. Aliasing can be prevented by preceding the address with a backslash. Normally the sender is not included in any alias expansions, for example, if ‘john’ sends to ‘group’, and ‘group’ includes ‘john’ in the expansion, then the letter will not be delivered to ‘john’.

Flags

−baGo into ARPANET mode. All input lines must end with a CR-LF, and all messages will be generated with a CR-LF at the end. Also, the ‘From:’ and ‘Sender:’ fields are examined for the name of the sender.

−bdRun as a daemon. This requires Berkeley IPC.

−biInitialize the alias database.

−bmDeliver mail in the usual way (default).

−bpPrint a listing of the queue.

−bsUse the SMTP protocol as described in RFC 821. This flag implies all the operations of the −ba flag that are compatible with SMTP.

−btRun in address test mode. This mode reads addresses and shows the steps in parsing; it is used for debugging configuration tables.

−bvVerify names only. Do not try to collect or deliver a message. Verify mode is normally used for validating users or mailing lists.

−bzCreate the configuration freeze file.

−CfileUse alternate configuration file.

−FfullnameSet the full name of the sender.

−fnameSets the name of the from person, that is, the sender of the mail. The −f flag can only be used by the special users root, daemon, and network, or if the person you are trying to become is the same as the person you are.

−hNSet the hop count to N. The hop count is incremented every time the mail is processed. When it reaches a limit, the mail is returned with an error message, the victim of an aliasing loop.

−nDo not do aliasing.

−ox valueSet option x to the specified value. Options are described below.

−q[ time ]Process saved messages in the queue at given intervals. If time is omitted, process the queue once. The time argument is given as a tagged number, with ‘s’ being seconds, ‘m’ being minutes, ‘h’ being hours, ‘d’ being days, and ‘w’ being weeks. For example, ‘−q1h30m’ or ‘−q90m’ would both set the timeout to one hour thirty minutes.

−rnameAn alternate and obsolete form of the −f flag.

−tRead message for recipients. To:, Cc:, and Bcc: lines will be scanned for people to send to. The Bcc: line will be deleted before transmission. Any addresses in the argument list will be suppressed.

−vGo into verbose mode. For example, alias expansions will be announced.

Options

There are also a number of processing options that may be set. Normally these will only be used by a system administrator. Options may be set either on the command line using the −o flag or in the configuration file.

AfileUse alternate alias file.

cDo not initiate immediate connection to mailers that are considered expensive to connect to. This requires queueing.

dxSet the delivery mode to x. Delivery modes are ‘i’ for interactive (synchronous) delivery, ‘b’ for background (asynchronous) delivery, and ‘q’ for queue only − that is, actual delivery is done the next time the queue is run.

DTry to automatically rebuild the alias database if necessary.

exSet error processing to mode x. Valid modes are ‘m’ to mail back the error message, ‘w’ to write back the error message (or mail it back if the sender is not logged in), ‘p’ to print the errors on the terminal (default), ‘q’ to throw away error messages (only exit status is returned), and ‘e’ to do special processing for the BerkNet. If the text of the message is not mailed back by modes ‘m’ or ‘w’ and if the sender is local to this machine, a copy of the message is appended to the file dead.letter in the sender’s home directory.

FmodeThe mode to use when creating temporary files.

fSave UNIX From lines at the front of messages.

gNThe default group id to use when calling mailers.

HfileThe SMTP help file.

iDo not take dots on a line by themselves as a message terminator.

LnThe log level.

mSend to me (the sender) also if I am in an alias expansion.

oIf set, this message may have old style headers. If not set, this message is guaranteed to have new style headers (that is, commas instead of spaces between addresses). If set, an adaptive algorithm is used that will correctly determine the header format in most cases.

QqueuedirSelect the directory in which to queue messages.

rtimeoutThe timeout on reads; if none is set, sendmail will wait forever for a mailer.

SfileSave statistics in the named file.

sAlways instantiate the queue file, even under circumstances where it is not strictly necessary.

TtimeSet the timeout on messages in the queue to the specified time. After sitting in the queue for this amount of time, they will be returned to the sender. The default is three days.

tstz,dtzSet the name of the time zone.

uNSet the default user id for mailers.

If the first character of the user name is a vertical bar, the rest of the user name is used as the name of a program to pipe the mail to. It may be necessary to quote the name of the user to keep sendmail from suppressing the blanks from between arguments.

Sendmail returns an exit status describing what it did. The codes are defined in <sysexits.h>

EX_OK Successful completion on all addresses.

EX_NOUSER Username not recognized.

EX_UNAVAILABLE
Catchall meaning necessary resources were not available.

EX_SYNTAX Syntax error in address.

EX_SOFTWARE Internal software error, including bad arguments.

EX_OSERR Temporary operating system error, such as cannotfork

EX_NOHOST Host name not recognized.

EX_TEMPFAIL Message could not be sent immediately, but was queued.

If invoked as newaliases, sendmail will rebuild the alias database. If invoked as mailq, sendmail will print the contents of the mail queue.

Restrictions

Sendmail converts blanks in addresses to dots. This is incorrect according to the old ARPANET mail protocol RFC 733 (NIC 41952), but is consistent with the new protocols (RFC 822).

Files

Except for /usr/lib/sendmail.cf, these pathnames are all specified in /usr/lib/sendmail.cf. Thus, these values are only approximations.

/etc/aliases Raw data for alias names

/etc/aliases.pag

/etc/aliases.dir
Database of alias names

/var/yp/src/mail.aliases
Raw data for alias names

/var/yp/DOMAINNAME/mail.aliases.pag
Yellow Pages alias database. DOMAINNAME is the YP domainname for the local area network.

/var/yp/DOMAINNAME/mail.aliases.dir
Yellow Pages alias database. DOMAINNAME is the YP domainname for the local area network.

/var/dss/namedb/src/aliases
Raw data for alias names

/var/dss/namedb/aliases.db
BIND/Hesiod alias database

/usr/lib/sendmail.cf
Configuration file

/usr/lib/sendmail.fc
Frozen configuration

/usr/lib/sendmail.hf
Help file

/usr/lib/sendmail.st
Collected statistics

/usr/bin/uux To deliver uucp mail

/usr/lib/mailers/arpa
To deliver ARPANET mail

/usr/spool/mqueue/*
Temp files

Museum

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