[Mimedefang] Parameters for tuning mimedefang

[David F. Skoll]

On Tue, 9 Sep 2003, Ron Hall wrote:

> 	Given that on a good(bad?) day the mailhub layer will
> 	see volume of 800 mail/minute what would be good starting
> 	values for mimedefang?

800/minute is a lot; it's 13/second.  I have achieved a throughput of
15/second on a dual-Xeon (2.6GHz) linux box with 1GB of RAM.  I used
a minimum of 5 and a maximum of 15 slaves, doing SpamAssassin and
Clam AV scanning.  (Actually, this was CanIt, so PostgreSQL got
thrown into the mix too.)

In the real world, you won't achieve this performance, because a
low-latency LAN is much easier on your server than the real Internet.

You probably need 3-5 fairly beefy servers equivalent to the above-mentioned
dual Xeon.  Set min slaves to 5 and max to (MEM/20), where MEM is the
size of physical memory in megabytes.

You want your Sendmail QueueLA and RefuseLA options set ridiculously
high.  THere's no point in artificially limiting your throughput.  However,
it's OK to set ConnectionRateThrottle; that setting can actually help.

You should also avoid doing network-related tests (RBL, DCC, Razor, etc.)
inside your mimedefang filter, because network latencies can cause slaves
to pile up and your machine to grind to a horrible death.

Regards,

David.