I liked a lot of things about qmail, but I found it annoying as a sysadmin, like in the 1.07 days, because you had to do all this patching. I eventually wrote a script that would take all the sources and patches that one needed to run a reasonable mail server, and turn them into an RPM that could be installed, because I couldn't just provide the patched, resulting RPMs.

There were a lot of great things about qmail. I really liked the envdir and how secure it was. But eventually I found the attitude behind it very tiring and switched to Postfix, which is a really great program.