2FA doesn't use authentication via email as it uses an Authenticator app to generate the TOTP code, but you may need to use a code send via email to confirm your identity or make important changes. You can disable 2FA via the Firefox account Settings page. *https://accounts.firefox.com/settings *https://support.mozilla.org/en-US/kb/secure-firefox-account-two-step-authentication *https://support.mozilla.org/en-US/kb/what-if-im-locked-out-two-step-authentication Do you still have access to the primary email account ? *https://support.mozilla.org/en-US/kb/forum-response-firefox-sync-verification-email-faq