Thunderbird uses the password that was set up in the webmail. To change a password this must be done via webmail account. There is usually an option 'Forgotten password' or similar. Thunderbird just stores and uses whatever password was entered when the mail account was setup. Tools > Options > Security > Passwords tab click on 'Saved Passwords' click on 'Show passwords' I would suggest your boss performs this as it is sensitive private data. The whole point of passwords is that they are kept secure and not divulged to anyone.