
Enter your name, email address, and account password and then click Continue.You'll see the Set Up and Email Account screen.The most recent version of Thunderbird is available on the Mozilla web site: New Account Setup (assumes you have never configured Thunderbird on the computer you are using)

While my question here is specifically about Thunderbird, I include this information as to me it suggests that something may recently have changed about Gmail which is causing problems for email clients in general, or that it is something in my system which is doing the same.These instructions are for Thunderbird for Windows. If I try to send an email I get "Authentication failed: 35-5.7.8 Username and Password not accepted". Sylpheed: No error messages on opening or when I click "Get, but no inbox messages are downloaded. Evolution: when I open it, a Google account authentication request window appears with error messages: "OAuth2 secret not found", "Access blocked", "Error 400: invalid_request". I have tried to set up two other email clients, Evolution and Sylpheed, to connect to my Gmail account. Following the steps suggested by Toad-Hall on the Mozilla Support forum. Tweaking the configuration as suggested by SumDumGuy on the Gmail Help forum Checking for previously saved passwords (there were none). Completely uninstalling and reinstalling Thunderbird (again). OAuth2 is set as authentication method. Thunderbird is set to always accept cookies.

I have no antivirus (Linux does not need one) or add-ons. I am 100% sure of my password and that it has been entered correctly. When I do this this error message appears: "Authentication failure when connecting to server ". I enter my name and then password, after which I am prompted to allow Thunderbird access to my account. When I open Thunderbird or click "Get Messages" I am presented with the Google login window. After reinstalling Thunderbird (102.7.1 (64-bit)) on Mint 19.1 I have a persistent authentication error with my Gmail account, so I cannot send or receive my emails through Thunderbird.
