I have at long last done a little more work on the mailserver project. The latest thing to report is the addition of dspam to filter out spam. In addition to this clamAV is also integrated.
The next step will be to do some more testing and then plug in another application which should make training and using the spam filter a little easier.
The documentation surrounding the addition of dspam and antivirus to the setup I am working on has been very hard to come by and in some cases is conflicting. Having made significant progress recently I am hoping to eventually have my setup production ready by the end of the year*. *Might as well give myself plenty of time.