We're now using dovecot for that stuff apparently (POP3 and IMAP server). Standard in FC2.
Be sure to grab the latest version (.9) from the Development tree. It fixes a number of bugs. Here's one mirror:
<http://download.atrpms.net/mirrors/fedoracore/development/i386/Fedora/RPMS/dovecot-0.99.10.9-1.FC3.2.i386.rpm>
Things fixed are listed on the dovecot home page:
<http://dovecot.org/>
