No it isnt because that address has never been used in that regard, and nothing like that has appeared in the last 5 or so years at that address until AFTER Xbox live sign up
Ive had another 40 today
I think it has got onto a re-sender/re-director as Im now getting "delivery error notifications" on emails Ive never sent
Then I would say the fault is with your PC and nothing to do with the xbox tbh
Sounds like one of those messenger viruses/trojans to me.
Or someone that just doesn't like you has used your email and signed up for loads of spam