XFMail is an X11 application for receiving
electronic mail. It implements most of its email
functionality internally so that it does not
depend on a lot of extra packages. It supports
POP3, MBOX, IMAP4, sendmail, and SMTP. It has
built-in support for interfacing with PGP, GPG,
ispell/aspell, faces, LDAP, and esound. It runs on
most Unix variants.