I had the same problem today. Make sure you are using the latest version of Thunderbird. Then do the following.

1. Select the `Account Settings` menu item from the `Tools` menu.

2. Click on your Gmail account and choose `Server Settings`.

3. Change the `Authentication method` pop-up menu to `OAuth2`.

4. Click on your `Outgoing Server`. Click the `Edit` button and change the `Authentication method` pop-up menu to `OAuth2`.

That solved the problem for me.

I got as far as #3. But could not find "outgoing server".

I got as far as #3. But could not find "outgoing server".

See this image (Click to View Image ). Outgoing Server is highlighted in blue.

Thank you. I found it and followed all your instructions but all I get is a looping page asking me to sign in to my Google account with my email address and phone #. It goes nowhere.

Do you have cookies enabled? See Automatic Conversion of Google mail accounts to OAuth 2.0 Authentication.

I followed all the instructions in your link, but still cannot receive gmail messages. I keep getting a Google page asking me to sign in to Google etc.

I followed all the instructions in your link, but still cannot receive gmail messages. I keep getting a Google page asking me to sign in to Google etc.

As a previous commenter suggested, make sure you have cookies enabled and have followed all of these instructions: https://support.mozilla.org/en-US/kb/automatic-conversion-google-mail-accounts-oauth20

As I told the previous commenter, I did all that and it didn't make any difference.

Here are the basics:

- change your security authorization to Oauth2 (do this for the server settings and also for the Outgoing (SMTP) server - two places - remove the password entries for the account (remove the entire entries both incoming and outgoing) - check to ensure that TB is set to accept cookies - Google will then step you through the authentication process for your PC.

I have provided these steps to a number of people today and each had success.

Are you using POP or IMAP? Are you running the latest release version of Thunderbird (v91)?

IMAP, and yes the latest version of TB. I finally solved the problem (I hope) by using the persistent Google web page and saying I lost my PW. Once I changed the PW I had to go through a series of permission steps to allow TB to access the account.