[Mimedefang] Lower spamassassin scores on newer faster server

[Delahunty, Mark]

Hi,

I have a server running mimedefang with spamasassin + fsav + sophos (no
sophie). It marks 65% of our incoming emails as spam.

I've set up another server with the same hardware, operating system and
mimedefang configuration except for 2 changes:

1. It uses clamd instead of sophos
2. It does no streaming

The new setup is much faster to process messages. I think this is because
sophos (without sophie) uses _lots_ of CPU. The trouble is, the new setup
marks less than 50% of our incoming emails as spam.

Anyone got any ideas why?

Is it possible that the older server was avoiding spam because it was
deferring incoming mails and the spammers do not retry deliveries? 

I'd be grateful for any suggestions anyone might have.

Mark Delahunty
Computer Centre
University College Cork
Ireland