Windows-mail-serv-error

" Account: 'Windows Mail', Server: 'pop.suddenlink.net', Protocol: POP3, Server Response: '-ERR An authentication mechanism MUST be entered', Port: 110, Secure(SSL): No, Server Error: 0x800CCC90, Error Number: 0x800CCC18"

This seems to have ocurred after Norton 360 was remotely down loaded and 360 was a lot different than the one it replaced. The reason it was replaced was that for the past week a dropdown would appear saying "Scanning e-mail 1 of 1 " then it would stay there looking dead and would not close unless re-started. Since I left computer on "Sleep" most of time, it stayed there for several days at a time.
The Asian techs were unable to find out why after several hours, decided to re-install. They are usually very good, so must have been something weird.

I have gone back to the WEB Mail that my server has available at suddenlink.net. But, I kind of liked windows better. I suspect that I will have to call Norton again as I can'r seem to find any help on Windows mail error.

Appreciate any help; suspect it has something about security, but not knowledgable enough to know what..