Can I recover the email of my lost account whilst only knowing its gamertag?

Hello. I haven't had an Xbox in many years but upon purchasing a new one I faced a problem. I can (I believe) remember my old Gamertag, however, upon several login attempts, I have resulted in confusion. I could have sworn I had the correct email address for the account when I had tried days ago, but all it did upon entering the email address and password for Microsoft was create a new account as if the previous one had never existed. Could you help me recover the original email address if possible? The Gamertag if I am not mistaken was, RhysIsNotSoCool. Thank you.

(ps. the Microsoft account I am using now is a different email and password to the account I'm trying to re-login to).

:)