thundrebird have lots of tools that helping to manage our account,
Click on Tools > Options, and switch to Security > Passwords.
Click on the Saved Passwords button. This displays a list of all email accounts with a saved password, and you may find other accounts listed here as well. This list may contain old email accounts that are no longer in use. Those can be deleted by the user by selecting them first and hitting the remove button thereafter.
All email account passwords that are stored in Thunderbird can be displayed by clicking on Show Passwords which you need to confirm when a prompt comes up.now you see very same listing displays the username, and site (that is the email provider) as well.
To change passwords, simply select the email account that needs to be changed and click on the Remove button. Next time Thunderbird tries to retrieve emails from removed accounts, it will prompt for a password for that account. Note changing passwords only applies to the stored password, the
