Free and open source webmail software
NOCC is a simple and fast Webmail client which can handle POP3, SMTP, and IMAP servers. It is written with PHP5 (uses sessions), has low requirements (no database, frames). Features multi-language support, MIME attachments, displays HTML messages.
Columba is an email client written in Java, featuring a user-friendly graphical interface with wizards and internalionalization support. Its a powerful mail management tool with features to enhance your productivity and communication.
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.
Allow to redirect (a.k.a. "remail") mail messages to other recipients
The Mailredirect extension for Mozilla Thunderbird and Mozilla SeaMonkey adds the ability to redirect one or more email messages to one or more recipients. The feature of email redirecting is also known as remailing or resending. The extension is an answer for https://bugzil.la/12916
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
Free and easy-to-use webmail script with AJAX interface. Supports POP3/IMAP accounts, SMTP, SSL. Users can check and send mail, use address book. Skins, non-English languages, UTF-8. MS SQL/MySQL/MS Access backends supported.
Open source SMTP/POP3/SSL e-mail server. Web admin panel, fast and stylish AJAX webmail, secure connections, SMTP authentication, multiple domains, account/domain aliasing, anti-spam, antivirus integration, mailing lists.
The Xoops POP3 Email client is a module/hack that will allow users to check their email via a xoops web site. This enhanced feature will be benificial to Xoops site managers and staff. This module is Powered by UebiMiau.
Zarafa is a complete replacement for MS Exchange under Linux. Zarafa has a full featured AJAX based webaccess which is completely in the Outlook "Look & Feel".