Open Source PHP Email Clients

SquirrelMail is a PHP-based Web email client. It includes built-in pure PHP support for IMAP and SMTP, and renders all pages in pure HTML 4.0 for maximum compatibility across browsers. It has strong MIME support and a flexible plugin system.

NOCC is a simple and fast Webmail client which can handle POP3 and IMAP mailboxes and sends email via SMTP. It is written with PHP, has low requirements (no database, frames). Features multi-language support, MIME attachments, displays HTML messages. The installation guide comes with the source code: https://sourceforge.net/p/nocc/code/HEAD/tree/trunk/webmail/docs/INSTALL If you encounter problems or bugs you can always try the current HEAD version: https://sourceforge.net/p/nocc/code/HEAD/tarball?path= Questions, bug reports or support requests are very welcome: https://sourceforge.net/p/nocc/_list/tickets Alternative source code repository: https://github.com/oheil/NOCC

EGroupware has moved to Github, please find all our downloads there: https://github.com/EGroupware/egroupware/releases EGroupware is a multi-user, web-based groupware suite. Currently available modules include: email, addressbook, calendar, infolog (notes, to-do's, phone calls), content management, wiki, project management, tracker, timesheet, knowledge base, CalDAV/CardDAV

Hastymail is a fast, secure, rfc-compliant, cross-platform IMAP/SMTP client application written in PHP providing a clean web interface for sending and reading E-mail. This version of Hastymail is no longer being developed. We are now working on a new version, Hastymail 3, AKA, "Cypht". http://cypht.org

Modest system requirements, decent performance, simple installation and upgrade, no database required - all these make RainLoop Webmail a perfect choice for your email solution.

AfterLogic WebMail Lite PHP is a free AJAX webmail application. Users can receive, view, manage, compose, and send email through web interface (IMAP and SMTP supported). Source code included.

Webmail with support for MIME mail, address book, plugin system, differrent themes and languages. Runs on PHP, MySQL and connects to IMAP servers.

NOTICE: Keep in mind that POP3ye is alpha software and by definition it is a long way from finished. POP3ye is a fully featured web-based e-mail client written in Object Oriented PHP 5. It ony supports the POP3 protocol.

Roundcube Webmail is a browser-based, multilingual IMAP client with an application-like user interface. Roundcube provides the full functionality you'd expect from an email client, including MIME support, address book, folder manipulation, message searching, and spell check. Roundcube is written in PHP and JavaScript.

Twiggi is a web-based groupware solution for Linux. It includes the ability to securely share information with co-workers either individually or via assigned groups. Twiggi features the following modules: IMAP webmail, calendar, todo list and more...

The most complete Business Webmail with Mobile client application for companies of all sizes. All the core functions for business like calendaring and integrated webmail, plus the capability of converting emails into business objects such as: quotes, invoices, marketing stuff, customer requests, project management and more. A simple way to have a unique flow of information from email request from customers to invoices!
You only have to choose which modules you want to activate and is done!
Built with PHP, loves MySQL but runs also on SQL Server and Oracle.