I'm using docevot in production since version 1.2 in conjunction with qmail/vpopmail and I'm fine with it. It's secure, easy to install and well documented. The community is alive and the support is good. In addition, you can easily manage sieve rules to filter your emails if you install dovecot/pigeonhole.
I recently wrote a guide for slackware here http://notes.sagredo.eu/node/28
, you may be interested to take a look to it.