This page will hopefully develop into a useful reference for postfix users all over the internet. Right now it's just a list of links and some advice. If you have postfix questions you should join the postfix-users list (see the main postfix website) or come and chat in #postfix on irc.freenode.net.
A guide to constructing an autoresponder (away message, Out-of-Office message) system when using the Virtual Delivery Agent as your main transport.
Why is Courier's POP3 server slow?
Results and recommendations of my investigation into why pop3dserver appeared to be CPU bound and very slow on my servers.
This is the main postfix website. There is more to this site than meets the eye. Look around and you'll find pages and pages of useful advice. Be sure to sign up for the postfix-users list.
VDA Softquota Patch
Postfix lacks the ability to restrict the size of a maildir mailbox. Xavier Beaudouin has created a patch that adds Maildir++ support to postfix. With this patch you can restrict mailbox sizes on a per-user basis, including Maildirs. (Xavier has handed this patch off to another author. I haven't used the new versions yet)
Ralf Hildebrandt's Postfix Page
Ralf is an active Postfix user and a big part of the Postfix support community. This page has many many useful configuration examples. Ralf has also published some good advice on how best to use ext3 filesystems on a postfix server.
Simon J. Mudd has written a very nice postfix RPM. It can easily be rebuilt to support MySQL, LDAP etc.
This is a nifty new document written by Dave Dribin and Keith Garner. They use much of the same software I do so I felt compelled to list their work.