Hello there We have read the message We try to help. We assume that you have an existing account for the Thunderbird version. And has a password saved for this You can use certain options in the program to solve this issue. We assume that you have an already installed account of the Thunderbird software. Here you choose extra - options - assigned passwords in your menu dropdown options. In your browser/menu you can choose security - passwords - find saved passwords. The option to choose saved passwords allows you to use the delete all button to clear the cache for security passwords used for this. The option to choose saved passwords allows you to use the delete all button to clear the security password cache for this purpose when restarting Thunderbird. Afterwards , hereby you will be asked for a new password. https://support.mozilla.org/en-US/kb/password-manager-remember-delete-change-tb It will only replace your Thunderbird password, not your Thunderbird account password. Greetings Firefox volunteer