I've run Thunderbird as my 1and1 email client for decades. I'm trying to setup a new Thunderbird V102 program with my 1and1 email account on a new Windows 11 laptop. I've completed the account setup with my name, email address and password, which it accepts. But then it shows the available configuration as IMAP with a warning that there's no encryption. I press the DONE button, but it then says "Unable to log in at server. Probably wrong configuration, username or password". But I know my username and password are correct, having tested them via 1and1. Any ideas about configuration please? I also understood that 1and 1 had encryption.