‘I have gmail as my default email client with Thunderbird and am unable to add my att.net account to Thunderbird. Thunderbird acknowledges a green message that the configuration is found in Mozilla ISP database for Thunderbird. When I click on "done" I get the yellow warning "Unable to log in at server. Probably wrong configuration, username or password". "Configuration was automatic setup as: incoming at POP 3 inbound att.net and outgoing SMTP outbound att.net. I have tried manual configuration and checked password to no avail. My att user ID has not changed in 20+ years and has always been my email address at att.net. I would like to add that I had a att.net account with Thunderbird until I did a Thunderbird recommended upgrade and then lost the att account including all my emails. Is there any way to recover this account?