Can't login to AT&T email on Mac running Lion from 1 account, but can from others. All settings for accounts are the same. AT&T verified settings OK. Can reset password & login ok for a few hours & then fails again. Login ok from iPad & iPhone?

i have the same exact issue, other email accounts at aol work fine, but only one of the att acccounts fails, the other works fine ... even tried erasing all accounts restarting and reloading all accounts to mail. still same account fails. also when i go direct to att and check mail, access works ok at their site, so it's only one account and with lion and apple's mail program, being rejected by the att server?? very frustrating. i'm glad my ipad and phone can access all accounts with out a problem.

Is this set up as imap or pop. What is the server you're using and ports?

Check the AT&T site for new info on email. Certain conditions apply depending on when the account was established.

Since you have other devices, you should really be using imap so all will stay synced.

Incoming server: imap.mail.yahoo.com port 993 SSL

Outgoing server: smtp.mail.yahoo.com port default. SSL

Another thing is to check Keychain. First use keychain first aid to verify that it is ok. Then find all passords for that account and delete them. There may be multiple passwords for it, so check for all. Go back into mail prefs and reinput the passwords for the account.