I actually wrote a script for Ubuntu server (works on 13.04) that encapsulates most of this tutorial. It doesn't include ClamAV or Spamassassin, but does everything else. You end up with a server that uses three mysql tables.

But then I discovered that Virtualmin does all of what this tutorial does, with an understandable u/i and all of the same capabilities from Dovecot/Postfix/saslauth. Doh!