D.M.Chapman@??? (D.M.Chapman) [Tuesday, September 03, 2002 6:57 PM]:
> Ok, we currently have a couple of mail hubs running exim 3 with
> mailscanner. These are shipping something like 40000 emails a day in
> term (each - 80k in total).
I'd farm the load of virus scanning off to a separate box with fastish hard
disks (heck, you could just build a fairly cheap pentium machine with a
large scsi hard disk), rather than burden your mailhubs. Ditto with the
spamassasin setup.
Whatever virus scanning solution you use, you will eat CPU (and disk IO)
heavily - so you might want to get the mail right off your mailhubs, instead
of tying up your queues with inbound and outbound mail.
Spamassasin is another resource hog.
Even then, with both virus scanning and spam filtering, a reasonably busy
but older spec / less powerful machine will chug along fairly well, till
something like a large infestation of Klez / Sircam, or a dictionary attack,
comes along.
To reduce the load on your machines, I'd suggest running something like LDAP
or MySQL so that your mailhubs have a reasonable view of your userdb
@ukc.ac.uk (need not have access to the actual LDAP server - but replication
could be considered...). Accepting a ton of mail to random non existent
senders (most of it spam, so will be trapped by spamassasin) will drive up
your processing costs a lot.
--srs
