Running Thunderbird 115.14.0. I have a gmail account which has been working fine with POP3 for years. The settings are: Server Type: POP Mail Server Server Name: pop.gmail.com Port: 995 Connection security: SSL/TLS Authentication method: OAuth2 I changed the password on Google, but now I cannot get my email account to work. When I try to retrieve emails, I get a popup box titled Enter credentials for <email>@gmail.com on pop.gmail.com. There's a box to Sign in to continue to Mozilla Thunderbird Email. My email address is filled in. But when I click the Next button, I get a Google error 400... and it says "The server cannot process the request because it is malformed. It should not be retried. That's all we know." The URL in the popup box is 1209 characters long. I cannot get beyond this. Any advice?