So I logged in to Xbox live today and it prompted me that I should look over my email and see if It's still valid. I looked it over, and it turns out that email was not an email I remember using for my gamertag/account/whatever. I then went and logged in to this website using an email I DO remember using, and it logged me in with the same gamertag. The emails were different, and the passwords are obviously different too, and yet I can log into the same account with different emails.
I had my xbox for quite a while, and i created that gamertag quite a while ago, so is it possible that I made that gamertag with a different email, and that the gamertag is linked to two different emails (If it even asked for a email)?