Duplicate of https://support.mozilla.org/en-US/questions/1252901 If you had read the reply to your original post, you would know to click on the word 'Passwords' in your picture. To make the subsections easier to see, open Edit/Preferences(Windows:Tools/Options)/Advanced/General/Config. editor and double-click the preference ''mail.preferences.inContent'' to true to have Preferences (Options) appear in a tab instead of a window.