I also going to say to look at your school tech support. School email address quite offen require a lot of funky settings on them to work correctly. I know here at Texas Tech it requires you VPNing and some other settings none of which are standard.
Mind you the tech suport page is really helpful and very detailed on how to set it up with step by step instration that does include pictures for several diffence programs including OSX.
The guy above posted the basics of it but I would suggest going your school to see exactly what the requirements are.