One of my Email accounts stopped working. I was getting a message saying server error. My other email account works just fine using the same AT&T Email. I deleted the account that failed from Thunderbird and then tried to reinstall it. Now when Thunderbird try to verify the Email address and password it fails. If I use the AT&T.net website and log into this account the account works just Fine. I have used both of these Email accounts in Thunderbird for about a year until today. Both on my computers are doing the same failure. Thanks Jim D