I'm sorry to say that this site is now gone. I originally set it up as a wiki hoping that other people would update it, but it's been at least 5 years since the last update. I hate leaving out-of-date directions online and the site had become packed with blog spam, so I removed it.
You can find more up-to-date directions here:
If you really want something from the original site, you can grab a copy of it here from the Internet archive:
Personally, I found the system I described too much trouble to maintain. Between the false positives and directory harvest attacks, I was spending way too much time keeping the system running. A few years ago I switched my company over to Postini (http://www.postini.com) and recently I switched my personal email server over to the free Google Business Standard Edition ( http://www.google.com/apps/intl/en/group/index.html) which includes anti-virus, anti-spam and imap support.