Vim-based e-mail client using MH and perl/Tk, intended as an replacement editor for Exmh but can be used standalone also. Support for GnuPG and passphrase caching. (Evim can only *send* e-mail!)
Gnome-Jupiter is planned to become a MUA supporting multiple POP3-Accounts. First aim is a stable SMTP/POP3 combination. IMAP is planned for the future.
pabber allows you to access the Exchange Global Address List and add entries to your .addressbook file
mvm is Xlib only plugin manager for Linux, providing a system of panes for different kinds of plugins. At this time plugins for file management and pop3 mail client are available.
Ishmail is a powerful and convenient email tool. Until recently, it was a commercial flagship product developed by HAL Computer Systems (then H&L Software). It was released under the GPL in May, 1999.
Pygmy is a GNOME mail client written in the Python programming language
Eridu is a web based groupware package written in PHP that aims to provide all the functionality expected of a professional groupware package such as MS Outlook+Exchange or Lotus Notes+Domino.
MultiMail is an offline mail packet reader for Unix and other systems. It currently supports the Blue Wave, QWK, OMEN, OPX and SOUP formats. It has a full screen, color user interface, built with the curses library.
CSCMail is an X/Gtk based MUA. It supports the POP3 protocal and can also read mailspool files/directories. It supports multiple accounts, filters, GPG, MIME, Spellchecking, HTML Mail (view only) and a host of other features.
A Full Featured E-Mail client with support for SMTP, POP3, Full IMAP, LDAP support for a global address book (anonymous and authenticated) unlimited private address books, todo lists, a personal calendar, spell checking support.
Cronos II is a MUA (or Mail Client) written from scratch over the GNOME library using C. This MUA is intended to be fast, light and powerful. It has support for POP3, Spool, SMTP, Plugins and many other protocols and features.
A Mail Program for Gnome.
An extremely configurable portable GUI email and news client for Windows/Unix (including OS X) with IMAP, POP3, SMTP, and NNTP support, SSL, flexible address database, Python scripting, powerful filtering, and many other features for advanced users.
Spruce is an X11 mail client written with the Gtk+ widget set. It is geared towards being extremely small and fast, supporting all the common features that users want or need without sacrificing usability or functionality
The program will provide integrated email and instant messaging for the Gnome desktop environment.
Spam Pesters Admins about Mail-abuse. This script automatically extracts sites from a spam mail and mails administrators of those sites to complain!
MailDB adds a database back-end to an IMAP server for features such as "virtual" mail folders (msgs appearing in multiple folders), "view" folders (dynamic results of searches), etc. The DB is inherently multi-user, allowing msg reference counting.
MFMail is a simple Python-program to mail one or more files from the command-line as a MIME-multipart message.
Geedot aims to be a lightweight, fully (and only) HTML 4.01 and CSS compliant and functional web browser for X. It uses the gdtoolkit widget set which is very fast and lightweight - yet also infinitely and easily expandable.
Claws Mail is a GTK+ based, lightweight, and fast e-mail client and newsreader. Supports POP3, APOP, IMAP, SMTP, SMTP AUTH, NNTP, LDAP, multiple accounts, spell-checking, addressbook, SSL, GPG, filtering, i18n, & more. It is further extended by plugins.
RFC 2425 defines a MIME Content-Type for Directory Information. This library contains necessary methods to parse information blocks arranged in such a manner.
fruMailer is a cross platform MUA written in both Java and Perl. The GUI is based off of the toolbar-and-windows idea behind the GIMP.
Note! Code and issues are maintained at https://github.com/sba1/simplemail. SimpleMail is a simple to use but powerful mail client. It supports the SMTP, POP3 and IMAP (in a simple form) protocols. Furthermore, among much other features, it is capable of showing HTML mails and can identify spam mails by using a Bayesian filter.
This is a full-featured email client for the KDE enviroment. It has the better things about two email clients, MSOutlook(r) and Netscape Mail (r), and some other new features, japanese input with kinput2