Configuration Options

Afile

Use the named file as the alias file. If no file is specified, use alias in the current directory.

aN

If set, wait up to N minutes for an "@:@" entry to exist in the alias database before starting up. If the entry does not appear in N minutes, rebuild the database (if the D option is also set) or issue a warning.

Bc

Set the blank substitution character to c. Unquoted spaces in addresses are replaced by this character.

c

If an outgoing mailer is marked as being expensive, don't connect immediately. This option requires queueing.

dx

Deliver in mode x. Legal modes are:

i	Deliver interactively (synchronously).
b	Deliver in background (asynchronously).
q	Just queue the message (deliver during queue run).
D	Rebuild the alias database if necessary and possible. If this option is not set, sendmail will not rebuild the alias database until you explicitly request it to do so (by using sendmail -bi).

ex

Handle errors by using mode x. The values for x are:

p	Print error messages (default).
q	Print no messages; just give exit status.
m	Mail back errors.
w	Write back errors (mail the errors if user not logged in).
e	Mail back errors and always give zero exit status.

Fmode

Set the UNIX file mode to use when creating queue files and "frozen configuration" files.

f

Save UNIX style "From" lines at the front of headers. Normally these lines are assumed to be redundant and are discarded.

gn

Set the default group ID for running mailers to n.

Hfile

Specify the help file for SMTP.

I

Insist that the BIND name server be running to resolve hostnames and MX records. Treat ECONNREFUSED errors from the resolver as temporary failures. In general, you should set this option only if you are running the name server. Set this option if the /etc/hosts file does not include all known hosts or if you are using the MX (mail forwarding) feature of the BIND name server. The name server is still consulted even if this option is not set, but sendmail resorts to reading /etc/hosts if the name server is not available.

i

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

Ktimeout

Define the maximum amount of time a cached connection is permitted to idle without activity. The timeout is given as a tagged number, with "s" for seconds, "m" minutes, "h" hours, "d" days, and "w" weeks. For example, "K1h30m" and "K90m" both set the timeout to one hour thirty minutes.

Ln

Set the log level to n.

Mx value

Set the macro x to value. This option can be used only from the command line.

m

Send to "me" (the sender) even if the sender is in an alias expansion.

Nnetname

Set the name of the home (local) network. If the name of a connecting host (determined by a call to gethostbyaddr()) is unqualified (contains no dots), a single dot and netname will be appended to sendmail's idea of the name of the connecting host.

Later, the argument of the SMTP "HELO" command from the connecting host will be checked against the name of the connecting host as determined above. If they do not match, "Received:" lines are augmented by the connecting hostname that sendmail has generated so that messages can be traced accurately.

n

Validate the right-hand side when building the alias database.

o

Assume that the headers may be in an old format, in which spaces delimit names. This option actually turns on an adaptive algorithm: If any recipient address contains a comma, parenthesis, or angle bracket, it will be assumed that commas already exist. If this flag is not on, only commas delimit names. Headers are always written with commas between the names.

Paddr

Add "postmaster" address addr to the "Cc:" list of all error messages.

Qdir

Use dir as the queue directory.

qfactor

Use factor as the multiplier in the function to decide when to queue messages rather than attempting to send them. This value is divided by the difference between the current load average and the load average limit (x option) to determine the maximum message priority that will be sent. This value defaults to 10000.

rtime

Cause a timeout on reads after time interval.

Sfile

Log statistics in the named file.

s

Be super-safe when running; that is, always instantiate the queue file, even if attempting immediate delivery. sendmail always instantiates the queue file before returning control to the client under any circumstances.

Ttime

Set the queue timeout to time. After this interval, messages that have not been successfully sent are returned to the sender.

un

Set the default user ID for mailers to n. Mailers without the S flag in the mailer definition run as this user.

v

Run in verbose mode.

xLA

Use LA as the system load average limit when deciding whether to queue messages rather than attempting to send them.

XLA

When the system load average exceeds LA, refuse incoming SMTP connections.

yfactor

This factor is multiplied by the number of recipients and added to the priority. Therefore, this value penalizes messages with large numbers of recipients.

Y

Deliver each job that is run from the queue in a separate process. Use this option if you are short of memory, since the default tends to consume considerable amounts of memory while the queue is being processed.

zfactor

This factor is multiplied by the message class (determined by the Precedence field in the user header and the precedence declaration lines in the configuration file) and subtracted from the priority. Therefore, messages with a higher class are favored.

Zfactor

This factor is added to the priority every time a message is processed. Therefore, this value penalizes messages that are processed frequently.