It's a gmail address. I adopted early enough that [email protected] was still available. The way that works with google is that you can punctuate it or capitalize it any way you feel good about it. Generally, I use firstname.lastname, but that also means I own everything from f.i.r.s.t.n.a.m.e.l.a.s.t.n.a.m.e@gmail to firstnamelastname@gmail.
I've tried the logical combinations that might get to him (he's got a different middle name than me, which lead me to believe that he might have the email firstname.m.lastname@gmail, where middle initial and first letter of last name are the same), but none of them lead anywhere, which has led me to conclude that the guy's just a f'n moron.
Sounds like you really tried to help the guy out and clear things up. Might be time to start sending dildos.