Do you understand that you first need to change the password with your mail provider?

When you have done that and Thunderbird finds it doesn't have a password that works, it will (if all is working normally) ask you to enter the new password.

You could have edited your saved passwords in-situ within Thunderbird, but now you have erased them, that possibility is passed and gone. Just right-click or double click a password that you need to edit.

Thanks for your response. I need advice on how to change my password with my provider.

Starting from the beginning, please send instructions on how to re-set my password, as if it were a new account.

Thank you very much.

Someone, somewhere, has given you an email account to use. They will have a webpage where you can, usually, log in to edit your email account. Failing that, there may be phone number or email address you can contact for help.

In most cases, your email provider can be identified from what appears after the '@' in your email address.

Thank you again for your responses. I think I have successfully changed my password and master password in Thunderbird, but I still can not gain access to my inbox.

I have typed in the password many times, closed out thunderbird, and re-opened to try again.

Sometimes, it appears to accept the password, because the prompt appears "enter master password." When I enter master password, however, it says "login failed." Any suggestions are greatly appreciated.