can't remember which email account I used to set up my Firefox account?
Have had Firefox for many years, now trying to sync iMac to a new Mac book, can't remember which email address I used to set up account therefore can't change password to set up sync ... how to find out which original email account?
Alla svar (1)
When you do not remember the password of the Sync account and thus would have to request a new password then this will reset all data stored on the Sync server. This happens because this password is used to encrypt the data, so only that original password can decrypt the content on the server. In that case it won't matter what email address you would use to set up Sync on the new computer because the original data is lost anyway. That is how Sync works and should always make sure that you do not forget the name (email) and password of the Firefox account you used.
You can try to log in to the Firefox account via this website.