Suddenly can't send or receive mail

I can't seem to send or receive messages all of a sudden. I have iCloud, system 10.7.2. In my Mail Preferences - Accounts, I see that my incoming mail server is dim and says p99-imap.mail.me.com. In the Mail Connection Doctor I see that the connection to the server is green - no login required. However, everything else is red. All accounts. It says, Trying to log into this smtp account failed. Verify that username and password are correct. I have done so but still no change. It also says that my outgoing server icloud is offline, which I don't understand because I am online. What gives? Thanks for your help. Soon please!