Firefox doesn't do email it's strictly a web browser, thus it doesn't have anything to do with an ''address book''. If you are using Firefox to access your mail, you are using "web-mail". You need to seek support from your service provider or a forum for that service. If your problem is with Mozilla Thunderbird, see this forum for support. [https://support.mozillamessaging.com/en-US/home] <br /> or this one <br /> [http://forums.mozillazine.org/viewforum.php?f=39]