On Tue, Jan 24, 2006 at 02:01:55PM -0200, Eduardo wrote:
> Hello!
> Sorry to send another email about the same subject. But my mail server
> crashed so i couldn't see the answers.
>
> I am calling my spamassassin service in SMTP time with some ACL rules in
> my exim4 configuration file. I start the SA service, start exim4 service
As far as I had the same problem, while I work on our
new/future exim+amavis+spamassassin-MTA, it stems from
'too many SMTP-connections in parallel' and in my case it
forced me after a few tests to move from 'spamassassin by ACL'
to 'scanning by pipe / in queue-runners'.
After you stop/restart the server, all MTAs which waited for
your server to come up, will 'crowd in' to deliver. So your
number of parallel incoming connections will be at its maximum.
If you do spam-checks 'by ACL' (in the SMTP dialog), you'll
need spamd-access for each connection in parallel, which
nearly always will either crash the server by overload,
or begin to let spam through (or defer connections) by timeout
(too many connections to one spamd).
Therefore we changed our spam-check to the other method
'by pipe', only checking for spam 'in the queue'.
This way, we can tell exim to accept the mail, put it
into the queue ('queue_only'), and then set the number of
parallel queue-runners exactly to the maximum capacity of
the spam-filter. This visibly slows down delivery at a whole,
but it should never force the server into thrashing.
The ideal setup though would be adapting to the load, scanning
by ACL, until too crowded, then switching to 'scan later' in
the queue, but I did not yet understand exim THAT far.
Stucki (postmaster of math/inf/mi.fu-berlin.de)
--
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