Split from this thread.

Unable to send or receive messages for the Bellsouth (dixon4421) account. The host 'pop.att.yahoo.net' could not be found. Please verify that you have entered the server name correctly.

Server: 'pop.att.yahoo.net'
Windows Live Mail Error ID: 0x800CCC0D
Protocol: POP3
Port: 995
Secure(SSL): Yes
Socket Error: 11001