I know this problem has come up in the past, but it seems that it has never been resolved. Neither of us have any spaces in our gamertags, and for some reason I am able to send him mail just fine, but when he tries to send anything to me it says that my gamertag doesn't exist. We are mutual friends on xbox live and he does show up under Social>Friends for me, so I'm not sure what we can do. Any suggestions?