SENDMAIL(8) System Manager's Manual SENDMAIL(8)
sendmail - send mail over the internet
/usr/lib/sendmail [ flags ] [ address ... ]
Sendmail sends a message to one or more people, routing the message
over whatever networks are necessary. Sendmail does internetwork for-
warding as necessary to deliver the message to the correct place.
Sendmail is not intended as a user interface routine; other programs
provide user-friendly front ends; sendmail is used only to deliver pre-
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, e.g., if
`john' sends to `group', and `group' includes `john' in the expansion,
then the letter will not be delivered to `john'.
-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 exam-
ined 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 compat-
ible with SMTP.
-bt Run in address test mode. This mode reads addresses and
shows the steps in parsing; it is used for debugging con-
-bv Verify names only - do not try to collect or deliver a mes-
sage. Verify mode is normally used for validating users or
-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 (i.e., 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
-n Don't do aliasing.
-oxvalue Set option x to the specified value. Options are described
-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 time-
out to one hour thirty minutes.
-rname An alternate and 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. Nor-
mally 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 configu-
ration 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 queue-
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 - i.e.,
actual delivery is done the next time the queue is run.
D Try to automatically rebuild the alias database if neces-
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 ter-
Ln The log level.
m Send to ``me'' (the sender) also if I am in an alias expan-
o If set, this message may have old style headers. If not
set, this message is guaranteed to have new style headers
(i.e., 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
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.
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 User name not recognized.
EX_UNAVAILABLE Catchall meaning necessary resources were not
EX_SYNTAX Syntax error in address.
EX_SOFTWARE Internal software error, including bad arguments.
EX_OSERR Temporary operating system error, such as "cannot
EX_NOHOST Host name not recognized.
EX_TEMPFAIL Message could not be sent immediately, but was
If invoked as newaliases, sendmail will rebuild the alias database. If
invoked as mailq, sendmail will print the contents of the mail queue.
Except for /usr/lib/sendmail.cf, these pathnames are all specified in
/usr/lib/sendmail.cf. Thus, these values are only approximations.
/usr/lib/aliases raw data for alias names
/usr/lib/aliases.dir data base of alias names
/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/net/bin/v6mail to deliver local mail
/usr/net/bin/sendberkmail to deliver Berknet mail
/usr/lib/mailers/arpa to deliver ARPANET mail
/usr/spool/mqueue/* temp files
biff(1), binmail(1), mail(1), aliases(5), sendmail.cf(5), rmail(1),
DARPA Internet Request For Comments RFC819, RFC821, RFC822;
Sendmail - An Internetwork Mail Router;
Sendmail Installation and Operation Guide.
Sendmail 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).
4th Berkeley Distribution SENDMAIL(8)