Q: 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!