Are you clearing cookies when you close Firefox?

no i haven't. unless it does it automatically.

-> click '''Firefox''' button and click '''Options''' * '''Privacy''' panel -> '''History''' section -> ''under'' '''Firefox will:''' ''select'' '''"Use Custom Settings for History"''' -> REMOVE Checkmark from '''Permanent Private Browsing mode''' ** place Checkmarks on 1) Remember my Browsing History 2) Remember Download History 3) Remember Search and Form History 4) Accept Cookies from sites -> 5) Accept Third-party Cookies -> ''under'' '''Keep Until :''' ''select'' '''They Expire''' -> click '''Exceptions''' button and click '''Remove''' button for all entries which have status set to other than '''Allow''' -> Now Type addresses of websites whose Cookies you want to be stored by Firefox e.g. mail.live.com , login.live.com , hotmail.com , msn.com , mail.yahoo.com , login.yahoo.com , yahoo.com , mail.google.com , google.com , etc. & click '''Allow''' button for each of these websites (One by One) -> click Close ** REMOVE CHECKMARK from CLEAR HISTORY WHEN FIREFOX CLOSES * '''Security''' panel -> place Checkmark on '''Remember Passwords for sites''' -> click '''Exceptions...''' button and click '''Remove All''' button -> click Close -> Click OK on Options window -> Restart Firefox ------------------------------------------------------------------------------------------ -> Go to your Email Website * Enter Username & Password * place Checkmark on '''Keep Me Signed-in''' or '''Remember Me''' * click '''Log-in''' or '''Sign-in''' button * Firefox will ask if you want Firefox to Remember your Username & Password (attached screenshot) on this site * click the '''Remember Password''' button Check and tell if its working. ------------------------------------------------------------------------------------------ -> IF you use '''Clear Recent History''' feature, DO NOT select '''Cookies, Forms and Search History, Active Logins, Site Preferences''' * https://support.mozilla.com/en-US/kb/Clear%20Recent%20History#w_what-things-are-included-in-my-history -> IF you use Privacy Cleanup softwares like CCleaner etc., DON'T SELECT FIREFOX IN ITS SETTINGS. These softwares can be responsible for Deleting your Firefox Settings.