HP-UX Mailing Services Administrator's Guide (B2355-91064)

value according to your system size. Do not set ConnectionCacheSize to a
value greater than 4.
• The ConnectionCacheTimeout(K) option specifies the maximum time that
any cached connection is permitted to remain idle. When the idle time exceeds
this value, the connection is closed. This number must be small (less than 10
minutes) to prevent Sendmail from using too many resources from other hosts.
The default ConnectionCacheTimeout value is 5 minutes.
How Sendmail Improves Mail Queue Performance
Mail queue performance is impacted by the number of entries in the queue directories.
Multiple Queue Directories improves mail queue performance in Sendmail. This feature
facilitates the parallel processing of mail by spreading process loads across multiple
disks, thereby improving the queue performance. UNIX files take a long time to open
when entries in the directories exceed 100.
In order to use multiple directories, you must supply the QueueDirectory option in
the sendmail.cf file with a value ending with *.
For example, if you specify the following in the configuration file, all the directories or
links to directories that begin with g will be used:
O QueueDirectory=/var/spool/mqueue/g*
If there are five directories, g1, g2, g3, g4, and g5, Sendmail uses all five directories
when the Sendmail daemon is restarted. Mail is randomly assigned to the queue
directories. Do not change the queue directory structure when Sendmail is running.
You can flush individual mail queues by specifying the following on the command
line:
sendmail -q -O QueueDirectory=/var/spool/mqueue/g1
sendmail -q -O QueueDirectory=/var/spool/mqueue/g3
You can use the mailq command to display the mail queue, as shown in the following
example:
#mailq
/var/spool/mqueue/g1 is empty
/var/spool/mqueue/g2 (1 request)
--Q-ID--- -Size- --Q-Time-- ----------Sender/Recipient--
gBJ2va 02544 5 Wed Dec 18 21:57 root root
/var/spool/mqueue/g2 is empty
/var/spool/mqueue/g3 is empty
Total Requests: 0
32 Mailing Services Overview