For some time now I have used the premise to always use a dedicated E-Mail Alias for every site I register to. Living by that rule, I always tend to tell all the users having an account on my server (mostly my family) to do the same. The drawback of this was that I became the personal admin of everyone and as Admins are known to be very lazy - it soon became a problem I wanted to outsource. Well - it has happened. the MX-Tools interface is available to registered users where they can take care of their aliases as their Mail-Server password reset.
It's Laziness has however not left the UI on that functionality. Some more functions have been added so that Blacklist, sender/recipient access configuration and some more can also be handled through the UI.