sendmail(8)

NAME

sendmail − send mail over the internet

SYNTAX

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

DESCRIPTION

The sendmail program sends a message to one or more people, routing the message over whatever networks are necessary. The sendmail program does internetwork forwarding, as necessary, to deliver the message to the correct place. The sendmail program is not intended as a user interface routine. Other programs provide user-friendly front ends, while sendmail only delivers the pre-formatted messages.

With no flags, sendmail reads its standard input up to a control-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 are:

−ba Go 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.

−bd Run as a daemon. This requires Berkeley IPC.

−bi Initialize the alias database.

−bm Deliver mail in the usual way (default).

−bp Print a listing of the queue.

−bs Use the SMTP protocol as described in RFC821. This flag implies all the operations of the −ba flag that are compatible with SMTP.

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

−bv Verify names only: do not collect or deliver messages. This is normally used for validating users or mailing lists.

−bz Create the configuration freeze file.

−Cfile Use alternate configuration file.

−dX Set debugging value to X.

−Ffullname Set the full name of the sender.

−fname Sets the name of the “from” person (that is, the sender of the mail). −f 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.

−hN Set 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.

−n Don’t do aliasing.

−oxvalue Set option x to value (see below).

−q[time] Processed saved messages in the queue at given intervals. If is omitted, process the queue once. 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.

−rname An alternate but obsolete form of the −f flag.

−t Read 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.

−v Go into verbose mode: alias expansions will be announced.

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. These are described in detail in the Installation and Operation Guide. The options are:

Afile Use alternate alias file.

c On mailers that are considered “expensive” to connect to, don’t initiate immediate connection. This requires queueing.

dx Set 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.

D Try to automatically rebuild the alias database if necessary.

ex Set 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.

Fmode The mode to use when creating temporary files.

f Save UNIX-style From lines at the front of messages.

gN The default group id to use when calling mailers.

Hfile The SMTP help file.

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

Ln The log level.

m Send to “me” (the sender) also if I am in an alias expansion.

o If 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.

Qqueuedir Select the directory in which to queue messages.

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

Sfile Save statistics in the named file.

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

Ttime Set 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,dtz Set the name of the time zone.

uN Set 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.

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

EX_OKSuccessful completion on all addresses.

EX_NOUSERUser name not recognized.

EX_UNAVAILABLECatchall meaning necessary resources were not available.

EX_SYNTAXSyntax error in address.

EX_SOFTWAREInternal software error, including bad arguments.

EX_OSERRTemporary operating system error, such as “cannot fork”.

EX_NOHOSTHost name not recognized.

EX_TEMPFAILMessage 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

Converts blanks in addresses to dots. This is incorrect according to the old ARPANET mail protocol RFC733 (NIC 41952), but is consistent with the new protocols (RFC822).

FILES

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

/usr/lib/aliasesRaw data for alias names
/usr/lib/aliases.pag
/usr/lib/aliases.dirData base of alias names
/usr/lib/sendmail.cfConfiguration file
/usr/lib/sendmail.fcFrozen configuration
/usr/lib/sendmail.hfHelp file
/usr/lib/sendmail.stCollected statistics
/usr/bin/uuxTo deliver uucp mail
/usr/net/bin/v6mailTo deliver local mail
/usr/net/bin/sendberkmailTo deliver Berknet mail
/usr/lib/mailers/arpaTo deliver ARPANET mail
/usr/spool/mqueue/*Temp files

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