Can't set up Gmail account in Thunderbird

Question

This was working fine until I had to reinstall Windows. If it makes any difference, I chose this time to install Thunderbird portable, and it's currently at v115.8.0

I go "add existing account" and enter my details. Thunderbird recognizes that it's Gmail and fills out the required fields

I click "Done", and it takes me to Gmail for authorization

I click "Allow" and now Thunderbird says

The Gmail permissions are fine

So, what am I doing wrongly, and how can I fix it? The user name & password are 100% correct. I tried copying them from a text file and logged in ok at gmail.com, but when I past them to Thunderbird, I get the above.

Answer 1

From this user support thread in the Mozilla Thunderbird support forums the issue seems to be accepting cookies:

“Open TB Options/Privacy & Security, check the box to accept cookies (so OAuth authentication can complete), remove the passwords from Saved Passwords, restart TB, enter the account password in the OAuth window when prompted. Check also that the authentication on the outgoing gmail server is OAuth2.”

Answer 2

Same issue but no luck with existing fix I found online:

1. Turn on cookie permission (source)
2. Remove all related already saved passwords related to the Gmail account (including the SMTP servers even) (source)
3. Use the app password from Google account (source)
4. ...

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How I solve the issue:

1. Turn on cookie permissions

2. Remove existing saved passwords for the Gmail account

3. Go with normal steps to add Gmail account, can even leave password empty.

4. Let thunderbird get the default setup for Gmail account

5. Manually change the IMAP and SMTP authentication method to be "normal password authentication" (this might not be literally the name for that option 'cause I was not using English version) instead of OAuth2.

   The magic happened in my case was that once "normal password authentication" was chosen, the auth page comes up, in which I can input the Google account password to complete the process.

6. Remove the saved password again (I did this but I don't think this should be required). Then change IMAP and SMTP server config back to use OAuth2 this time.

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• Actually I remember the auth page came up for me once before I turned on the cookie permission. As a result, I kept wondering if the root cause was that thunderbird completing an auth process but eventually failing due to cookie writing denied. And this cause all following OAuth2 trying fails. Until try to use a different authentication method?

• Just Found a post suggesting the same method: Try changing the Authentication method for the IMAP account to Normal Password and remove the currently stored value for Oauth. Then close and restart Thunderbird to be sure that the cached values are cleared.

• This method keeps jumping out after I solved this and submitted the answer (/facepalm)

  like: I had same problem and find solution when I changed Authentication method from: 0Auth2 to Normal password

• Anyway, in order to keep my Gmail account safely and being too lazy to set up a new account for testing, I stopped digging XD

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It took me half day to fix this issue while crawling answers and trying out. Sincerely hope the above steps will help someone.