Evolution is the GNOME mailer, calendar, contact manager, and communications tool. Evolution represents the next step forward in GNOME applications. The tools which make up Evolution will be tightly integrated with one another and act as a seamless personal information-management tool.
The AMC Mail Client is a mail client striving to be a robust, fully gnome-compliant mail reader. However, the AMC Mail Client differs from other mail clients in that it attempts to utilize existing tools for mail retrieval, sending, and filtering, (fetchmail, sendmail/smtp, procmail). By not going through the process of reinventing the wheel, the AMC Mail Client starts out as a fully equipped client that inherits all of the features of these existing tools.
GSendMail is a simple, standalone mail composition tool using the GTK+ toolkit. It allows you to fill in From, To, CC, and Subject fields, and compose a text/plain message in a fixed-width text area with word-wrapping. It does some sanity-checking on typed addresses, but beyond that it is frill-free (no HTML, no attachments, no address book). This program makes it possible to click on mailto: links in Mozilla/Netscape installations without the mail component.
GMailWatch is a GNOME Panel Applet that displays a summary of incoming mail (sender/subject) rather than just an icon. It's similar to the old xmailwatcher utility (and uses some of the same code), and is also based upon mailcheck (of gnome-core). The user can change the size of the panel applet.
SQmaiL is a mail reader for GNOME that stores all its mail in a MySQL database. This makes it blazingly fast for very large (10000 message) mail databases. It supports hierarchical vfolders based on SQL queries, so you can have your mail automatically categorized based on arbitrarily complex SQL expressions. It has excellent MIME support on both incoming and outgoing mail. Mail can be fetched from local spool files and POP servers. Full picons support and partial xface support is available, to give your mail that personal touch. The user interface is customizable with Glade, and the program itself is easily extensible with Python. Some command line utilities allowing access to the mail database without X are available.