Yeah, or he typed it in wrong once and it's saved as an autofill in his browser so he keeps doing it by accident. He's very interested in buying trucks and cruise holidays, and he recently got a private investigator to run a background check on someone. Sounds like a charmer
He's probably just typing his own email address in wrong. Maybe you can track him down on Facebook, if you can be bothered.
I get these kinds of emails too. Usually it's spam, but sometimes it seems legit. I usually just ignore it