Lots of copies of SMTP process, _postfix user

We have a Lion server (10.7.3) running on an older Mac Mini (Mid 2007). We have been having slow downs recently and I started to do some poking around at it...

Does anyone have any idea why I might have many many copies of a SMTP process, associated with the _Postfix user, started by LaunchD? It kind of goes through cycles: low end is about 15 processes, high end is about 125 (no easy way to count that I can find, not in Activity Monitor at least...ok, just figured out a terminal command: "ps -ef | grep -c smtp".

Other oddities:

400+ GB of VM space (cycles with the SMTP processes it seems; ranges between 350GB and 500GB)

Free memory: 9MB - 150MB (cycles); system has 4GB of physical memory, 3GB addressable (limitation of the hardware)

A number of Python instances, for _calendar

Perl5.12 process: there were 38 running before I restarted the machine, now there is only 1.

HTTPD processes: 4 currently

We don't really have too much running on this server (that I am aware of 🙂 ). FileMaker Server runs (its primary purpose, severely restricted by this slowness), Dropbox, various built in things (iCal, web, mail all turned on, but not used - to my knowledge).

Thanks,

J