This document describes how to install a PureFTPd server that uses virtual users from a MySQL database instead of real system users.
To get an encrypted home directory under Debian Linux, only a few steps are necessary.
I have found that this is the easiest combination that allows you to serve Virtual Domains, and Users. With this it's also very easy to implement webmail systems like SquirrelMail.
Here you will find a list of all available configuration options for lighttpd