Hello Pierre,

Try adding your gmail account to Thunderbird with these exact settings if Thunderbird does not automatically detect them.

Protocol: IMAP Server: imap.google.com Port: 993 SSL: SSL/TLS Authentication: OAUTH2 Username: <your email>

Let me know if this configuration solves your issue.

Thanks Roman. The detection was correct. I have checked manually the configuration and it was correct, as you suggest and as proposed on the Thunderbird page.

Notice that I had gmail installed before and had problems following the 2-factor authentication. I then decided to remove gmail and reinstall it. Hence my problem... I guess that the imap.google.com is somewhere hidden in the system.

Best regards, Pierre

Thanks for double-checking that Pierre.

Another Thunderbird user has had a similar error message when adding a second gmail account. Question link: https://support.mozilla.org/en-US/questions/1283682.

Deleting your Thunderbird profile (located in '%appdata%') would delete your messages and setting configurations stored locally on your computer, and would give you a fresh start, which worked for the above user. You could backup your Thunderbird profile before attempting this if you are unsure.

https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

If this is unacceptable to you, an alternative could be creating another Thunderbird profile for this account. https://support.mozilla.org/en-US/kb/using-multiple-profiles#w_starting-the-profile-manager