Configuration Variables

Here is a list of some of the common variables used in the .mc file and their purpose:
Variable Purpose
confSMTP_LOGIN_MSG This defines the one-line message which is displayed when a remote MTA connects to sendmail's SMTP port. Variable expansion is done for many variables, including:
$j
local hostname
$v
version of the sendmail binary
$Z
version of the sendmail.cf file
$b
current time
This can be changed for fun to something like $j sendmail $v/$Z ready to serve your every whim at $b.
confMAX_MESSAGE_SIZE This is the maximum message size allowed for local delivery. I recommend setting this to 5242880 (5MB) to avoid mail bombs.
confPRIVACY_FLAGS This allows you to set some restrictions on what other users are allowed to find out about sendmail's operation. Common values are:
authwarnings
Issue warnings about authenticity of header information.
restrictqrun
Only allow root to run the mail queue manually.
restrictmailq
Only allow root to see the contents of the mail queue.
noexpn
Do not allow the SMTP EXPN command, which allows remote users to see the result of an alias expansion on the local machine.
novrfy
Do not allow the SMTP VRFY command, which allows remote users to verify the existance of a user account on your machine.
Multiple privacy flags can be specified, seperated by commas.
confQUEUE_LA Load average at which sendmail puts incoming email into the queue rather than attempt to deliver it immediately.
confREFUSE_LA Load average at which to stop accepting new incoming SMTP connections.


Mark D. Roth <roth@feep.net>