First, test your password by logging in to your provider's webmail:
http://mail.yahoo.com .
If that works, it proves you have the correct username and password.
A likely reason for the username/password failing in Windows Mail 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.
Email scanning in any antivirus must be disabled, for reasons
explained here:
http://thundercloud.net/infoave/tutorials/email-scanning/index.htm
Gary VanderMolen, Microsoft MVP (Mail)
"SP2 help" wrote in message
I get the following error message when I open my mail and don't know where
to start to correct this.
Server: 'pop.att.yahoo.com', Protocol: POP3, Server Response: '-ERR [AUTH]
invalid user/password', Port: 995, Secure(SSL): Yes, Server Error:
0x800CCC90, Error Number: 0x800CCC92
