Automatic Conversion of Google mail accounts to OAuth 2.0 Authentication

Starting from version 91.8.0, when updating from a version lower than 91.8.0, Thunderbird will convert the authentication method of Gmail accounts to OAuth 2.0 to help users comply with Google's requirement of OAuth 2.0 for Gmail logins. These changes are required by Google.

Ensure that your Thunderbird Gmail account is set to OAuth2

Outgoing Server (SMTP)

1. Do ≡ > Account Settings
2. Select your account (e.g. [email protected]) from the account list on the left.
3. At the bottom of the settings pane, look for Outgoing Server (SMTP).
4. Click on the Edit SMTP Server… button on the right.
5. In the SMTP Server dialog, ensure that Authentication method is set to OAuth2.
6. Click on the OK button to confirm your SMTP Server settings.

Incoming Server

1. Do ≡ > Account Settings
2. Select your account (e.g. [email protected]) from the account list on the left.
3. Underneath your account entry, select the Server Settings subsection (if it is not visible, you may need to toggle the > button first).
4. Ensure that Security Settings > Authentication method is set to OAuth2.

How to avoid or correct an OAuth failure caused by rejected cookies

First, verify your general setting for cookies in Thunderbird:

• Do ≡ > PreferencesSettings > Privacy & Security > Web Content.
• Look at the checkbox Accept cookies from sites.

If Accept cookies from sites is not checked, do one of the following and then go through the OAuth login process again:

• Create an exception to accept cookies from Google:
  • Click the nearby Exceptions… button to open the Exceptions - Cookies dialog.
  • In the Address of website input box, enter https://accounts.google.com.
  • Pick Allow, then Save Changes.
• Alternatively, accept all cookies:
  • Set the checkmark for Accept cookies from sites.

After you have gone through the OAuth process, if you prefer, you can again reject cookies, because receiving and sending mail will work with cookies rejected. But rejecting all cookies or removing the exception has the disadvantage that when the OAuth token for Gmail access expires at some date in the future, the OAuth dialog will show up and fail again until you accept the required cookies.

For greater detail about cookies, see the article Privacy panel - Remote content and cookie settings in Thunderbird.

How to avoid or correct an OAuth failure caused by disabled javascript

1. Do ≡ > PreferencesSettings > General
2. From the bottom right corner of the General settings pane, click Config Editor.
3. Copy or type this into the Search preference name searchbox: javascript.enabled
4. You should now see a single search result line for the setting javascript.enabled.
   • If javascript.enabled is true, no change is needed.
   • If javascript.enabled is false, you need to change it to true by clicking the Toggle button to the right.

Check if the proper authentication tokens have been saved

• Do ≡ > Settings > Privacy & Security > Passwords> Saved Passwords.
  • If account authentication was set to OAuth2 and the OAuth login was successful, you should see entries for each username (gmail account) of the form

oauth://accounts.google.com (https://mail.google.com/ …)

Note: The oauth entry is an OAuth2 authentication token, and not a password.

• If account authentication was set to OAuth2 and OAuth login was not successful, check your password entries for providers of the following form and delete them:

imap://imap.gmail.com (imap://imap.gmail.com)

smtp://smtp.gmail.com (smtp://smtp.gmail.com)

If you're still having problems, you can ask a question in Thunderbird support.