A likely reason for the username/password failing is account corruption.
One thing you should try as a possible quick fix is to delete that corrupted
mail account, restart Windows Mail, then recreate that account.
If that doesn't fix it, more drastic measures will have to be taken.
Which antivirus are you running?
As a minimum, email scanning in the antivirus must be turned off,
although that may not be sufficient to eliminate all bad effects.
In a worst case scenario, your antivirus may need to be uninstalled.
If turning off the email scanning function does not resolve your problem,
consider upgrading to Windows Live Mail, because it is less prone to
suffering bad effects from overly aggressive antivirus programs.
http://download.live.com/wlmail
Email scanning in any antivirus must be disabled, for reasons
explained here:
http://thundercloud.net/infoave/tuto...ning/index.htm
--
Gary VanderMolen, Microsoft MVP (Mail)
http://mvp.support.microsoft.com/def...le/vandermolen
"Suzanne Michael Catering" <Suzanne Michael
> wrote in message news:8C0384EA-6782-4FB3-A482-...
> When I try to send or recieve emails a pop-up window says titled windows
> security appears requesting I verify my username and password for my mail
> server. When I enter the information, which I know is correct, it goes back
> to the same popup. When I cancel or X out of the pop up it gives me the
> following error:
>
> Account: 'Suzanne Michael Catering', Server: 'fpostoffice.isp.att.net',
> Protocol: POP3, Server Response: '-ERR login failed', Port: 995, Secure(SSL):
> Yes, Server Error: 0x800CCC90, Error Number: 0x800CCC92