In English: ''Set Master Password , but do not enter a password directly off the password dialog box , you can view the message '' ''In Tools - Options - Security - Use a master password , after setting up replication of the password each time you restart Thunderbird mail password dialog box will pop up , but once I direct canceled password , can view all of the mail directly so very safe . While this allowed the master password can be limited to e-mail , but allowed to receive new mail address is the only installation components : saved_password_editor-2.8.3-fx + sm + tb As a master password that seem too is gone. Please improve '' Already answered: Please do not post duplicate queries: https://support.mozilla.org/en-US/questions/1059518#answer-723489 Master Passwords are designed to protect the mail account passwords from prying eyes, they do not protect from viewing emails. all this is fully explained here: * http://kb.mozillazine.org/Master_password You should use - set up 'User Accounts' on computer to protect against access to your desktop view, access to Profiles etc.