Wanderlust is a mail/news management system with IMAP4rev1 support for Emacs.

 * Implementation in elisp only.
 * Support of IMAP4rev1, NNTP, POP(POP3/APOP), MH and Maildir.
 * Integrated access to messages based on Folder Specifications like Mew.
 * Key bindings and mark processing like Mew.
 * Management of threads and unread messages.
 * Folder mode to select and edit subscribed folders.
 * Message cache, Disconnected Operation.
 * MH-like Fcc (Fcc: %Backup is possible).
 * Full support of MIME (by SEMI).
 * Draft editing of mail and news as a same interface.
 * Icon based interface for the list of Folder (XEmacs and Emacs 21).
 * Skip fetching of a large message part of MIME(IMAP4).
 * Server side searching (IMAP4), internationalized searching is available.
 * Virtual folder.
 * Compressed folder.
 * Automatic expiration of old messages.
 * Automatic refiling.
 * Draft templates.