Can't use gmail (Mac)

[tanstaafl]

"Then I get a message that Thunderbird wants to access certain things. I click allow."

That is normally when it creates the OAuth2 token (third page in the popup where you allow the access). Software that uses a local proxy such as localhost based web server running on your computer can cause that to fail. This supposedly is due to the loopback connection to 127.0.0.1 that Thunderbird uses.

I've found threads that claim "With OAuth2 authentication you cannot use app passwords, you'll have to use your main Google account password." So my prior suggestion was wrong. See https://support.mozilla.org/en-US/questions/1373706

[ralphot]

Why should it be so difficult to get a gmail account work in Thunderbird??

[ralphot]

Its hard to help you without knowing how far you got in the sequence to create a OAuth2 token. That is why I asked you the last three questions.

I changed everything to POP3 and now it works. Didn't need OAuth2 after all, plain password works fine. But it needed the app password created at Google too.

Can you explain why??

Thanks for your efforts.

[ralphot]

"Then I get a message that Thunderbird wants to access certain things. I click allow."

That is normally when it creates the OAuth2 token (third page in the popup where you allow the access). Software that uses a local proxy such as localhost based web server running on your computer can cause that to fail. This supposedly is due to the loopback connection to 127.0.0.1 that Thunderbird uses.

I've found threads that claim "With OAuth2 authentication you cannot use app passwords, you'll have to use your main Google account password." So my prior suggestion was wrong. See https://support.mozilla.org/en-US/questions/1373706

Yes, suspected that, therefore I use POP now with no problem.