Overview of the Queue
The sendmail queue is implemented by
placing held messages into one or more directories. Prior to
V8.10, there was only one directory, and its name was
usually mqueue. Now, the directory or
directories to be used are specified in the configuration
file with the QueueDirectory
option (QueueDirectory on page 1070):
OQ/var/spool/mqueue ← pre-V8.7 form O QueueDirectory=/var/spool/mqueue ← beginning with V8.7 O QueueDirectory=/var/queues/q.* ← V8.10 multiple directories
If the QueueDirectory
option is missing, the name defaults to mqueue
. The location
should never be relative (as mqueue
). When it is wrongly specified as
a relative path name, it is taken as relative to the
location where sendmail is run. Because
the sendmail daemon is typically
started from an rc file at boot time,
such relative locations are usually relative to the
root (/
) directory.[175]
After sendmail has processed its configuration file, it does a chdir(2) into its base queue directory and does all the rest of its work from there. In the first two lines of the previous example, the base queue directory is /var/spool/mqueue. In the last line, the base queue directory is /var/queues. This change into the base queue directory has three side effects:
Should the sendmail program fault and produce a core dump, the core image is left in the base queue directory.
Any relative pathnames that are given to options in the configuration file are interpreted as relative to the base queue directory. (This is not ...
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