qmail is an Internet Mail Transfer Agent (MTA) for UNIX-like operating systems. It’s a drop-in replacement for the Sendmail system provided with UNIX operating systems. qmail uses the Simple Mail Transfer Protocol (SMTP) to exchange messages with MTA’s on other systems.
QmailAdmin
QmailAdmin is a Web control panel for the administration of qmail/vpopmail-based POP, IMAP, LDAP, or Web mail accounts, forwarding, aliases, autoresponders, and mailing lists. It is perfect for ISPs, Web hosting sites, or companies that want to provide a nice interface for managing email accounts. It works with qmail, vpopmail, sqwebmail, and courier-imap.
Downloads and Documentation
http://sourceforge.net/projects/qmailadmin/
QmailWebmin
qmailWebmin is a Webmin module for administrating a qmail mailserver. Its main feature is the easy virtual accounting with separated POP3 passwords. Based on work found on qmail.org, it aims to be as standard as possible with a default qmail installation. This Webmin module is aimed at lazy administrators and persons with little knowledge about general UNIX administration.
Downloads and Documentation
http://sourceforge.net/projects/qmailwebmin/
Qadmin
Qadmin is an administration tool for Qmail, written in PHP and MySQL.
Downloads and Documentation
http://www.enzolutions.com/qadmin/home.php
QmailAdminWeb
QmailAdminWeb is an admin suite for Qmail+MySQL with a Web GUI. It has the ability to add and remove users, change user’s passwords, build the forwarding database, and more.
Downloads and Documentation
http://qmailadminweb.sourceforge.net/
oMail-admin
oMail-admin is a PHP-based Web frontend to qmail and vmailmgrd. It can be used by domain owners and single users to easily administer their mail accounts without bothering the sysadmin. Its features include mailbox/alias management, auto-responder (vacation-like) support, support for changing passwords, and translations for the French, English, Swedish, Chinese, Japanese, Spanish, Italian, Russian, Danish, Romana, Czech, Nederlands, and German languages
Downloads and Documentation
Qubit
Qubit (Qmail Ultimate Backend Integration Tool) is a fully Web-based qmail server configuration and administration suite. It is based on the qmailrules qmail server installation style. It has the same features as other similar tools (like vqadmin and qmailadmin), and it also gives you full control to administer your server with all sorts of features and applications.
Downloads and Documentation
http://sourceforge.net/projects/qubit/