Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail (Mandriva 2009.1 x86_64)

This document describes how to install a Postfix mail server that is
based on virtual users and domains, i.e. users and domains that are in
a MySQL database. I’ll also demonstrate the installation and
configuration of Courier (Courier-POP3, Courier-IMAP), so that Courier
can authenticate against the same MySQL database Postfix uses.

. Read the rest at howtoforge.net.