I have recently configured several CentOS virtual mail servers. It took me quite a while to figure it out the first time or two, but has gotten significantly easier since then. Initially, I pieced information together from a half-dozen or so various other howto’s that were either designed for a different distro, or were outdated (or both).
So when I put together another server last night, I made careful notes when installing it and generated a howto document.  It walks a user all the way from a clean CentOS 5 install, through to a functioning virtual mail server. It uses postfixadmin as a web interface for managing the domains and accounts. All domain and user information is stored in a MySQL database.  Postfix is installed for the MTA, and Dovecot for the POP3/IMAP server.   It doesn’t require system accounts for any of the users. All mail services are accessible over encrypted SSL/TLS protocols.
Helllo,
i like this solution because there must not so much default settings be changed. Also the spamassassin integration doesn’t require a special configuration. But until now I found no solution to drop a as spam marked mail to /dev/null. (I think procmail is not used and creating a procmailrc does not change anything) Is there a way?
Greetings Chris
@Chris:
Procmail should work for that, but you would have to change postfix to use procmail for delivery instead of delivering it directly to the inbox itself. I’ve not done that before, so not sure what all is involved in setting it up. Check out HowToForge which usually has pretty good resources.