Thunderbird Gets a 400 Error Setting Up Gmail
Normally, setting up a Gmail account in Thunderbird is a breeze. It auto-detects all your settings, pops up a log-in window, you allow Thunderbird access, and boom – you’re set!
But if you’ve been using this copy of Thunderbird for a while, you may have changed some settings, and if by some chance you’ve turned off cookies in the Privacy & Security settings, the Google login won’t work, and you’ll get a very generic error:
400. That’s an error.
The server cannot process the request because it is malformed. It should not be retried. That’s all we know.
Fortunately the fix is easy:
- Go back into Privacy & Security.
- Turn cookies back on. (It doesn’t even need third-party cookies!)
- Set up the Gmail account.
- Turn cookies off again. (If you want to.)