Do you have Google Calendar or Google Contacts address book?

Of course I have it. But you must not be using aaa@gmail.com's Google Calendar or Google Contacts address book with Thunderbird.

The point is, when you added the mail account you were asked to sync Google Calendar and Contacts. Removing the mail account doesn't affect the calendar or contacts, so they keep asking for credentials. Unsubscribe the Google calendar and remove the Contacts address book in Address Book if you don't use them in TB.

I thank you for your thoughtful response. But still, I need your help.

I approved the Calender and Adress book links when I registered "aaa@google.com" on TB. I remember that. And when I removed "aaa@google.com" from TB, I removed it from the calendar. Therefore, "aaa@google.com" does not appear in the TB calendar. I have not done anything with the Adress book. I don't remember linking "aaa@google.com" to TB's address book.

What exactly should I do? I would like you to tell me. Be specific.

In Address Book, right-click an address book (might be named Address Book or Contacts), Properties, and see if it is synced with Google. If it is, right-click, Remove.

Thank you very much. Excellent! Resolved. I appreciate you very much. Thank you.