if you change your password, it must be done on the gmail website, then the old password must be deleted or edited in Preferences/Security/Passwords/Saved Passwords, for both the incoming and outgoing servers. This will work if the account uses normal password authentication. If the authentication is OAuth2, delete the old passwords (tokens) in Saved Passwords, then restart TB. When the OAuth window appears, enter the new password, and then Google will add a new token in the password manager.

One further complication, if OAuth is used, is you must have at least TB 60.9.1 or 68.2.1, due to a change in Google's OAuth.

Thanks for this reply. It sounds like it might work. I've tried some of these things. But I'll have to spend more time. Hopefully it will work because MailMerge with TB is great!

I've tried changing my password on Google. My problem is still with Thunderbird. It will not stop asking me for the password. I cannot get control back because it keeps having these request windows for the password to send a message. From what I can see the messages are all gone. But there must be one or something still calling for the password that it still won't accept. Thunderbird has been so wonderful over the years. I have a scholarship program in Haiti and I need to send our donors the news about the terrible situation in Haiti currently. Thanks!

What is your version of TB, and what is the authentication for the gmail account? Is the account POP or IMAP? Do you get the error message when sending a message without using Mail Merge?

Still having no success. My TB still is stuck on getting a password. And here is the message that is now coming:

Sending of the message failed. Failed due to unexpected error 80004005. No description is available. The message could not be sent using Outgoing server (SMTP) smtp.gmail.com for an unknown reason. Please verify that your Outgoing server (SMTP) settings are correct and try again.

I have force quit TB. I have downloaded a new TB V 68.3.0

There are several new passwords listed including one for OAuth. But I have shut off IMAP and enabled POP which I used for years prior to now with nothing like this happening.

My version is 68.3 I have canceled my IMAP choice and gone back to POP. Still TB opens up and produces the same message that it couldn't deliver the message (I don't think there are any more messages from my last MailMerge group.) By fiddling a bit I have been able to get the TB drop down to come and I can select various places. But... the response about the message not being able to be delivered still comes and freezes everything on the TB page.

It's moving me to seek another "client" much as I have loved TB for years.

Thanks.