openDialog("chrome://pippki/content/resetpassword.xhtml")  

Are you referring to an account password or the Primary password? If it's the primary password, here are instructions: # Choose Tools -> Developer Tools > Error Console, paste the expression: ''openDialog("chrome://pippki/content/resetpassword.xhtml") '' # the, press the Evaluate button. That will open a dialog asking you if you want to reset your password. If Evaluate is not seen, press enter key. # When prompted, press the Reset button. https://support.mozilla.org/en-US/kb/protect-your-thunderbird-passwords-primary-password#w_resetting-your-primary-password-if-you-have-forgotten-it All account passwords will be deleted and will need to be reentered. If the problem is your email account password, you need to contact your email provider to reset it