Tryed this many times never works , Microsoft employees over the phone don't have the power to unban gamertag , all they will tell you is to make a new account and appeal the ban via xbox forums
Unless you have a tier 3 extension and know how to connect now then no. All they have access to is CCF and no clearance for any enforcement action.
Best you can get in contact with via their main number is a tier 2 technical support agent. And even they aren't help most of the time.
I dont know but it makes sense right? If you delete the email it says EVERYTHING will be deleted too even your xbox live? so does that include the gamertag?