Etach
- Emacs extension for MIME attachments and detachments works in RMAIL and Mail modes.
- http://rulnick.com/etach/

Eicq
- ICQ client integrated into XEmacs.
- http://www.eicq.org/

Emacs/W3
- A web browser completely written in Elisp.
- http://www.gnu.org/software/w3/

Riece
- An IRC client for Emacs featuring multiple panes.
- http://www.nongnu.org/riece/index.html.en

Emacs-w3m
- A simple Emacs interface to a text-mode WWW browser.
- http://emacs-w3m.namazu.org/index-en.html

Emacs Wiki Mode
- A wiki-like publishing tool and personal information manager that allows to create a wiki on local system and can publish to HTML format.
- http://www.mwolson.org/projects/EmacsWiki.html

MUTT with Emacs
- Short guide for installation and use with emacsclient.
- http://heim.ifi.uio.no/~jani/mutt/muttemacs.html

Reading Lotus Notes Mail Using Emacs
- Use Pop3 to access the mailbox.
- http://www.dsm.fordham.edu/~moniot/cis-system/node15.html

Sending Authenticated Mail (rfc2554)
- For smtp sessions with gnus.
- http://www.pdc.kth.se/~jas/emacs-rfc2554.html

Supercite User's Manual
- Provides sophisticated facilities for the citing and attributing of message replies.
- http://www.delorie.com/gnu/docs/emacs/sc_toc.html

Insidious Big Brother DB
- An addressbook and contact management database for emacs mail and news clients.
- http://bbdb.sourceforge.net/

Wanderlust
- Uses IMAP to manage and read mail, strong Japanese support.
- http://www.gohome.org/wl/index.html

The Insidious Big Brother Database
- The creator, JWZ, still maintains a page with interesting historical information.
- http://www.jwz.org/bbdb/

The Mh-e Den
- Official site of the front end to the MH mailer, at Sourceforge.
- http://mh-e.sourceforge.net/

Mew
- An acronym of "Messaging in the Emacs World". Runs with Unix, Windows, OS/2, and supports folders, threads, mail aliases.
- http://www.mew.org/

VM Homepage
- The author, Kyle Jones, maintains the official page for this alternative to Gnus, Rmail, and the others.
- http://www.wonderworks.com/vm

Mailcrypt: An Emacs/PGP Interface
- Encrypt/decrypt mail with PGP 5.0 or GnuPG.
- http://mailcrypt.sourceforge.net/

Gnus Newsreader Homepage
- An acronym for Gnus Network User Services, a news and mail reader with threading, ratings, self documentation.
- http://www.gnus.org/