My email accounts in Thunderbird for att, gmail, sbcglobal, and charter have been working fine for years. A week or so ago my sbcglobal account stopped working. It was pretty close to the time my Thunderbird email program updated to 78.5.0. On inbound and outbound sbcglobal mail I get server errors stating my password is incorrect. When I attempt to access my email on web based access it works fine, so I know my password is correct. I changed my att email password to a auth2 more secure long one but I was never prompted to change my sbcglobal one and it continued to work fine. I even tried today to change the password to the new auth2 one on my sbcglobal account and also previous password versions I had and nothing works, I keep getting server error messages. I attempted to setup my sbcglobal account in windows 10 mail and it is responding similarly to the Thunderbird one. I've deleted accounts in both thunderbird and windows 10 mail and attempted to setup again and I'm right where I started again. I even used windows system restore to a date when I know sbcglobal was working and nothing changed. I've checked my firewall settings and see nothing there preventing my email accounts from working, besides my other account are working fine. I'm at a total loss, I've been experimenting since late last night. I've accessed blogs and forums and tried a variety of solutions and so far nothing has worked.