Qmail

qmail is a modern SMTP server which makes sendmail obsolete, written by Dan Bernstein, who also has a web page for qmail. qmail is a secure package. You can download netqmail 1.06 (Redhat RPMs, and Debian .debs, HP-UX, Gentoo, and OpenBSD ports) and redistribute qmail for free. You can get the "big picture" of how qmail is organized. You should read Life with qmail.

There is a discussion list and an announcements list for qmail users, maintained by Dan Bernstein using qmail, of course. There's also an archive. You can search it. It's also archived at The Aims Group, at Gossamer Threads, and in Mailbox-format archives. Charles Cazabon has written some guidelines for posting to the list. There is also an FAQ, providing answers to frequently-asked questions. qmail is now open source.

Dan's updated FAQ is also available in other file formats, and in Spanish.

A number of large Internet sites are using qmail: USA.net's outgoing email, Address.com, Rediffmail.com, Colonize.com, Yahoo! mail, Network Solutions, Verio, MessageLabs (searching 100M emails/week for malware), listserv.acsu.buffalo.edu (a big listserv hub, using qmail since 1996), Ohio State (biggest US University), Yahoo! Groups, Listbot, USWest.net (Western US ISP), Telenordia, gmx.de (German ISP), NetZero (free ISP), Critical Path (email outsourcing service w/ 15M mailboxes), PayPal/Confinity, Hypermart.net, Casema, Pair Networks, Topica, MyNet.com.tr, FSmail.net, Mycom.com, and vuurwerk.nl.

Charles Cazabon, Dave Sill, Henning Brauer, Peter Samuel, and Russell Nelson have put together a netqmail-1.06 distribution of qmail. It is comprised of qmail-1.03 plus the recommended patches and some documentation.