Hi there,
I use mail and entourage and citrix with Snow Leopard in a corporate office which is very PC centric.
I must say that I havent experienced the same issues - I connect to Corporate email servers, gmail and other mail hosts on a regular basis and dont experience these problems.
I have 30 odd years working with IT and have had (and support quite a number of macs..) When I have had issues with crashing etc. I have found that generally:
-confirming that the hardware (specifically 3rd party RAM) is ok
-updating with the combo pack (just in case something went screwy with an update)
Download and install this... when it is installing make sure all apps are closed..
http://support.apple.com/kb/DL1361
I understand that there may be other mitigating factors and I would encourage you to apply the pack and test it EXTERNAL to your campus. Initially with a new user and then with your existing account. Specifically I would recommended trying the connection from your ISP to a GMAIL account and see how you go.
I believe that that should be fine and it might restore some of your faith. Internal mail servers and lockdowns etc can be a challenge to sort out and its worth making sure oyu have a good baseline.
Wishing you luck.