ote that this address feature is about addresses (your location) and not about email addresses. Email addresses are normally handled by saved form data or by the password manager in case of a login form. *Settings -> Privacy & Security<br>Firefox will: "Use custom settings for history": "Remember search and form history" *https://support.mozilla.org/en-US/kb/control-whether-firefox-automatically-fills-forms *https://support.mozilla.org/en-US/kb/password-manager-remember-delete-edit-logins You can try to set these three ''extensions.formautofill'' prefs to "on" (without the quotes) if the default "detect" isn't working and possibly add your country code to "supportedCountries". *extensions.formautofill.available = "on" *extensions.formautofill.addresses.supported = "on" *extensions.formautofill.creditCards.supported = "on" Close and restart Firefox after changing these prefs. You can open the <b>about:config</b> page via the location/address bar. On the warning page, you can click "Accept the Risk and Continue" to open about:config. *https://support.mozilla.org/en-US/kb/about-config-editor-firefox