Large mail queues

Julian Field jkf at
Fri Feb 1 14:07:56 GMT 2002

Have you tried switching off spam detection, or using "Delivery in
Background = yes".
The sleep(30) is only used when there is very little/no incoming mail anyway.

Perhaps other people with large throughput might like to comment?
(I don't like the "-q1m" solution at all, it was suggested by someone else).

At 11:55 01/02/2002, you wrote:
>However we did have a few problems initially with very large mail queues
>building up when we went live. (From our usual number of about 600 to 15500)
>We did several things to improve matters and thought these might be of
>interest to others in similar situations.
>1. Changed the sleep(30) to sleep(2) (the delay time between mailscanner
>selecting the next batch to process) in mailscanner. We were finding the
>incoming mail building up faster than mailscanner could cope because of this
>delay. It would be nice if this were a configurable parameter.
>2. Once the queues had built up to this size things deteriorated further
>because of problems unix has with large directory sizes, and this slowed
>down mailscanner's ability to process the queue so we recreated the queues
>from scratch and started afresh.
>3. Sendmail change - this was not really anything to do with mailscanner,
>but it helped the faster delivery of local mail. We started an additional
>sendmail process for the output queue with parameter of -qRkcl (where kcl is
>our local domain) to process local mail.
>4.  The -q1m parameter on sendmail was used (as suggested in the FAQ).

Julian Field                Teaching Systems Manager
jkf at         Dept. of Electronics & Computer Science
Tel. 023 8059 2817          University of Southampton
                             Southampton SO17 1BJ

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