The error number by itself does not pin the problem down.
Right-click on your error message, copy, then paste it into a reply here.
We can't do much troubleshooting without the complete error message.
The host 'POP3' could not be found. Please verify that you have entered the
server name correctly.
Account: 'POP3', Server: 'POP3', Protocol: POP3, Port: 110, Secure(SSL):
No, Socket Error: 11001, Error Number: 0x800CCC0D
"POP3" is not the correct server name.
Your email account provider should have a help page on their website with
the correct server names and settings.
Some even have tutorials. If they don't have one for Windows Mail, use the
one for Outlook Express.
Or, if you tell us who provides your email account, perhaps someone can
help.