Completely Virtual Mail Server

[Lee W <debian-user@unassemble.co.uk>]

Hello,

I am trying to create a completely virtual mail server (i.e. no shell
accounts).

If itself this is not a problem as Postfix is capable of doing this
however, I wish to add a slight twist to the query.  Is it possible to
do Filtering as well.

I have STFW and searched the archives and come up with the usual
suggestions of using Postfix+Courier-IMAP+sqWebmail and similar
combinations, however they tend to break once you include procmail or
Maildrop.

Has anyone come up with a solution to this problem?

Regards

Lee