Unfortunately, TB 52 doesn't support OAuth2 authentication, which is the method currently recommended for gmail accounts. Did you allow access by 'less-secure apps' in the Google account settings?

http://kb.mozillazine.org/Using_Gmail_with_Thunderbird_and_Mozilla_Suite

Hello sfhowes!

Thanks for your reply and the reference http://kb.mozillazine.org/Using_Gmail_with_Thunderbird_and_Mozilla_Suite.

There were many options included in that reference, the one that I noted specially was that Gmail does not allow access to new accounts less than 3 months from email clients (like Tbird). The new account I opened was created on January 16, 2021 . So that may possibly be the reason my Tbird is unable to make a connection to download. The other information did not seem germane.

All my other Gmail accounts which Tbird connects to have 16-digit app passwords and work just fine. It's only the new account that is not able to connect.

I'm going to have to get to that new account directly via web access to Gmail for the time being, until the 3 month lifespan is accomplished before asking Tbird to do it along with my other accounts.

Thanks for your help.

The article states that the 90 day restriction only applies if you allow access by 'less-secure apps'. Even then, the restriction may not always be applied. But that isn't necessary if you set the authentication on the incoming and outgoing to OAuth2, the recommended method for gmail, Yahoo, AOL. Of course, that's not possible with TB 52, so you will either have to wait for 90 days, or perhaps find that the restriction is no longer imposed.

You will find increasing security restrictions as time goes on with Windows XP. Even IE11 on Windows 7 will be blocked from accessing gmail after March 15 2021.