MySQL users, Postfix, Dovecot & SquirrelMail with userprefs stored in mySQL

Name: MySQL
HomePage: http://www.mysql.com/
function: MySQL, the most popular Open Source SQL database

Name: Dovecot
HomePage: http://dovecot.org/
function: Dovecot is an open source IMAP and POP3 server for Linux/UNIX-like systems, written with security primarily in mind.

Name: Squirrel Mail
Homepage: http://www.squirrelmail.org/
function: Webmail client, used to check e-mails from anywhere in world, via the internet, like gmail or hotmail

Name: Postfix
HomePage: http://www.postfix.org/
Function: (message transfer agent) postfix is program responsible for receiving incoming e-mails and delivering the messages to individual users

Name: PostfixAdmin
HomePage:  http://high5.net/postfixadmin/
Function: Postfix Admin is a Web Based Management tool created for Postfix. It is a PHP based application that handles Postfix Style Virtual Domains and Users that are stored in MySQL.

Mambo is an open source cms (content management system) it is used with conjunction with Mysql a database backend to store all the user information in, php a web based program language and Apache the worlds most used web server.

Name: Apache
HomePage: http://www.apache.org/
Function: Webserver

Name: MySQL
HomePage: http://www.mysql.com/
Function: MySQL, the most popular Open Source SQL database

Name: PHP
HomePage: http://www.php.net/
Function: developers to write dynamically generated webpages

Name: Mambo
HomePage: http://www.mamboserver.com/
Function: dynamic portal engine and content management system