I would like to use postfix as a front end for Exchange, to run spamassassin.

Ideally, the linux box would accept email from the net, run SA and then forward ALL mail to the exchange server (all mail destined for my domain, that is), with no local delivery and no checking to see if the recipient user exists (I do not want to have to synchronize the user database). The Exchange server is already configured to handle all that.

Basically, an MTA that runs SA with no MDA.

Currently, I have Postfix working with SA. Local delivery to /var/spool/mail works fine.

Thanks ahead of time!

Jed