Hmm, ok, Cyus seems to use something similar to the standard maildir format, just in a proprietary way. Can it store the mail in home directories still? My root directory is rather small due to everything going into users home directories.

Also, how does procmail work with it? For me, procmail simply manipulates the maildir file structure to put the mail in the right box. And what exactly is Cyrus? Just the IMAP server, or does it replace Sendmail for example?