This is about the primary email address. If you no longer use this email address, then try the email address you worry about your primary email. This is only possible if you have verified this email address. *https://support.mozilla.org/en-US/kb/change-primary-email-address-firefox-accounts *https://support.mozilla.org/en-US/kb/add-secondary-email-address-firefox-accounts You can login here with an email address to ensure that your Mozilla Account stays active. *https://accounts.firefox.com/signin *https://accounts.firefox.com/settings