Daniel Bernstein's home page for qmail.

Dave Sill's Life with qmail, the definitive resource for what might be called the qmail way.

Russell Nelson's unofficial qmail home page, a big reference portal for many qmail things.

Andre Oppermann's qmail resources, particularly The BIG Qmail PICTURE graphics in many formats and paper sizes. (Andre's site is also your first stop for qmail-ldap.)

Han Boetes' short article describes an optimal partition scheme for installing qmail on an OpenBSD system. Includes other insightful comments.

Bruce Guenter's site has a trove of useful qmail add-ons and utilities, including:

• syncdir
• qmail-qfilter
• relay-ctrl
• vmailmgr
• etc.

Frank Denis' site has many useful qmail resources. See in particular:

• The Qmail and ReiserFS Integration HOWTO
• qmail-link-sync.patch
• checklocalpwd-1.0.tar.gz, a checkpassword replacement
• etc.

Thinking about Postfix? It has gained currency as the "politically correct" alternative MTA, and may even be found installed by default with your latest OS. Here Jonathan de Boyne Pollard provides some excellent points of comparison with qmail.

Not everyone is a fan; here Mathias Andree posts his Qmail bugs & wishlist. Sample pout (section 5.1) about Bernstein's security guarantee: USD 500 are a ridiculous amount for the audit of qmail.

By Dave Sill, Apress, 2002. Dave's Life with qmail and more, in print.