Sendmail

is a secure, reliable, efficient, simple message transfer agent. It is designed for typical Internet-connected UNIX hosts. As of October 2001, qmail is the second most common SMTP server on the Internet, and has by far the fastest growth of any SMTP server.

DMail
is an easy to install, high performance, reliable and scalable mail server. Anything from a small personal mail server to a 10 Million user ISP mail system. Flexible authentication modules allow you to plug DMail into any existing user database. It includes many spam prevention mechanisms and the ability to run any of several virus checking packages of your choice.

Exim
is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet. It is freely available under the terms of the GNU General Public Licence. In style it is similar to Smail 3, but its facilities are more extensive, and in particular it has some defences against mail bombs and unsolicited junk mail in the form of options for refusing messages from particular hosts, networks, or senders. It can be installed in place of sendmail, although the configuration of exim is quite different to that of sendmail.

Nexor
provides high tolerance messaging and directory solutions to financial organisations, communications service providers and a variety of military, government and defence departments worldwide.

IMAP
(Internet Message Access Protocol) is a method of accessing electronic messages kept on a (possibly shared) mail server. This site provides information about IMAP-supporting software developed by the University of Washington and two IMAP-related mailing lists hosted by the UW. For more information about IMAP, see the IMAP Connection, a clearinghouse of IMAP information including an overview of IMAP, an inventory of IMAP products, and documents describing and evaluating IMAP.

IMC
The tables on this page describe some of the many features supported by IMC's members in their software and services. The tables are presented in a variety of formats in order to give the best view on a variety of web browsers.
The first table is the legend to the features listed in the tables. After that, there is a Java applet that allows you to keep the row and column headings on your screen as you scroll around the chart. (The applet is about 100K.) That is followed by a standard HTML table that may not fit on your screen, particularly if you are not using small fonts. The last two tables list the same information, first by IMC member company, then by feature.