I need to set up several gmail accounts in Thunderbird. The accounts exist; I can see email by going to gmail's webmail for them. I'm running Thunderbird 115.10.1 on Windows 11. I choose Tools > Account Settings > Add Mail Account then provide the name, email address, password, then TB validates the credentials with gmail's systems. I get a green light message saying that gmail found the entries. I then provide the appropriate POP3 server name and port address and the appropriate SMTP server name and port address and confirm security settings - all of which were verified and carefully edited when entered. TB then sends the information to google and after an very long delay returns a message saying the attempt failed, probably due to incorrect password or settings. All of the information and settings - including the password which was copied and pasted AND the same one used to log in to gmail webmail - are correct. Obviously, I'm doing something wrong but don't know what. The error message is so generic as to be unhelpful. Can anyone help me discover the problem?