[Exim] New mailhub/virus/spamassassin installation.

All.

My apologies for raising this question on the list as I know that it must
have been done to death in the past. I have searched the mailing list
archives but unfortunately there are so many related posts it is quite
impossible to see the wood for the trees.

This month I am set to implement a new mail server strategy. Comprising two
external facing mailhubs in a DMZ and two internal mail relays (through
which all local and remote mail will pass) which will also provide virus
scanning and spamassassin checking.

Because the virus checking will be performed at the second hop into my
institution, virus checking and rejecting at SMTP time is not really an
option. Instead I would like the relay tier to formulate a sensible e-mail
message to return to the sender. This is particularly important for local
senders as we use outlook here and rejecting at SMTP time with outlook
produces a message which would definitely result in a call to our IT
helpdesk.

I have used exiscan before with reject at smtp time behaviour, but as far as
I can see there is not an exiscan option to fail but with a generated e-mail
message. What would people recommend instead of exiscan that does offer this
functionality - amavis? Mailscanner? - What are you guys using in this kind
of scenario ?

I would be extremely grateful or any advice both on my outlined plan and on
appropriate virus scan enabling software etc. Also for those of you using
spamassassin - will it happily coexist on a virus scanning machine ? etc.

All advice, opinions, config snippets etc. gratefully received.

TYIA

Nigel Cass
Systems Engineer