Email problem

Hi, Every once in a while including yesterday, I will post something to send, and my email locks up. Won't send or receive. Usually I can re-boot and it will fix it. But this time, even deleting everything in my outbox, that does not work. I tried to restore to a different date, and that didn't work.

What it does, it tells me that my host address is wrong. How does this happen? I didn't do it. Where do I go to correct the address?

Thanks,

BTW, I have Firefox and Windows Live