For gmail you should look to this article for pointers. https://support.mozilla.org/en-US/kb/automatic-conversion-google-mail-accounts-oauth20 I would guess neither of your other accounts use oauth authentication which is a problem for those that attempt to lock down cookies and have antivirus software helping. My personal hate is Notons product because I have never managed to run the account wizard without having to mess with Norton to get the wizard to work. But they are all about as helpful as each other in messing you about.