sa-learn with remote Dovecot folders

Hi all!

The set-up I have is a classic one:

1. one or more Dovecot relay/directors Postfix SMTP servers in DMZ
2. one or more backend IMAP/SMTP servers on the inside network
3. There may or may not be separate incoming or outgoing designated SMTP servers. Now the desired functionality is (of course):
4. relay machines receive messages from outside AND inside
5. relays check for all the bad things (spam, viruses etc).
6. for incoming messages relays check for valid local users and reject messages for invalid users
7. after all checks are done incoming messages are transferred to the backend systems where they are accessed via the Dovecot directors

While all the above works nicely, the problem I have is how to train my spamassassin (used by amavisd) on the front ends when all messages are on the back ends. Of course transferring the spam detection procedures internally is not such a great option.Am I missing something? I tried googling for info but nothing substantial turned up.

Thanks.

-- Andreas Kasenides Senior IT Officer Dept. of Computer Science, University of Cyprus Tel: 22892714, Fax: 22892701 (5B4ANK)