I, too, stopped receiving my emails from my hotmail account yesterday.
So, i followed the link a few posts up, about how to reset everything. I clicked the cingular website, as that is the service I have. I logged in, and right after logging in, it displays what email address is currently being sent to my phone. I just deleted it, added it again, and it's up and working now.
Thanks for inadvertantly helping me!
