Free and open source webmail software
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.
YAM - The E-mail client for Amiga computers
YAM (short for Yet Another Mailer) is a commonly used MIME-compliant Internet mailer written for AmigaOS computers. It supports POP3, SMTP, TLSv1/SSLv3, multiple users, PGP, hierarchical folders, filters, a configurable GUI, an ARexx interface and more...
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.
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
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
Simple, modern & fast web-based email client
Modest system requirements, decent performance, simple installation and upgrade, no database required - all these make RainLoop Webmail a perfect choice for your email solution.
Elmo is a feature-rich console mail client for UN*X power users. It integrates functionality commonly realised by separate pieces of software in other mailers.
The OpenP2M is a software that lets you store and share files on your email account.
"Archive This" is an add-on for the Thunderbird email client that provides shortcuts for filing messages into folders rapidly and efficiently.