A simplePHP script which will monitor your mailboxes and display nearly real-time information about your users' POP mail inboxes, including sizes, last access times, and more in an easy-to-read-at-a-glance web based interface.
PoCoMy: Postfix + Courier + Mysql :: Webfrontend for administration. Features: Virtual domains, forwarding, aliases, sender aliases, multi user, multi language, privileges system, delegation of rights per domain, ...
MadMail is a simple Webmail client which can handle POP3, SMTP, and IMAP servers.
It is written with PHP (Sessions) an can displays HTML messages and MIME attachments.
Features multi-language support
No Database required
LIMeTool (pronounced like the fruit), is intended to be a simple and easy interface for managing accounts on an integrated Sendmail/LDAP/Cyrus IMAP installation. It's written in PHP and is realitively easy to configure and expand.