When I try to setup sync I get this error: Sorry. We’ve locked your account. The confirmation email we sent to xxxxx@fastmail.net was returned and we’ve locked your account to protect your Firefox data. I have setup 'accounts@firefox.com' as and entry in my fastmail address book (as suggested). Waited 24hrs (as suggested) and tried it again with the same results. If you need my specific email address please pm me.