Friends and Messaging plugins not sending email notification

I'm not getting messaging or friend notifications from my Wordress 3.0.1 multi-site install (in fact, I'm not getting ANY emails- even when new blogs are created). Anyone have a suggestion of where I should start looking? Gotta have emails sent as teachers will receive notification of student submitted posts for approval. I've tried my work email and my gmail - nothing (and nothing in spam). You guys rock...thanks in advance!
k

site url - http://www.burlesonisd.net/blog/