I posted a few weeks (possibly months) ago that I would get my guide to setting up a mailserver onto the site. Unfortunately I ran into a few security realted problems that needed to resolved. The good news is I have made plenty of notes of the process and it should just be a case of typing them up.
I hope to have the notes up soon after I have a basic secure working setup. This should take no more than a couple of weeks if I am able to dedicate time to the project.