What I would like is a POP3/IMAP and even SMTP proxy that uses the already build in SpamAssassin and ClamAV for scanning. Also it should be transparent for the users on the LAN so I can catch spam/virus for those who have configured personal email account on external mail servers. Today all local (corporate) emails are scanned nicely by SME (SA and ClamAV) but I need this for external servers as well. I shouldn't require any changes to the clients - then they will just disable it anyways....
Hence it needs to catch all requests to external POP3/IMAP/SMTP servers and send the data through SA/Clam.
Does anyone know of such solution?