stillin1:
A possible clue is in the account name given in the error message above - it reads "pop3.lineone.net". To me this means it's the incoming mail storage server, not a true account name like "
[email protected]"
If you can receive email sent to your Pipex email address then this is probably wrong, but if not, it's worth checking against the settings for another email account.
If you can send and receive email for any other accounts set up in OE, then this is the most likely cause.
Also, check
this Microsoft support page for more details.