Help me figure this one out?

I met a guy at work. We got a long great. It is rare I find anyone I can tolerate or get along with for long periods of time, whether at work, in public, or etc. I had a rough past full of insecurity and abuse. We email all the time.. I am married and I would never cross the line first off. This friend I will call him John. He has given me anything I wanted..like mp3's etc and again he has sent me 350 emails since I left the place we worked at together and while I worked there he sent 1300 emails over a 10 week period. I am probably seeing things in a way that it isn't meant to be taken as..like flirting etc... So I said, if you need space or want to end our friendship or if I have overstepped any boundaries that is now let me know. It is his decision because I don't, honestly. I am a great person once you see past the insecurity or emotional instability. I have always said Thank you for everything he has done for me and given me. What should I do now so I don't lose him as a friend because it is very rare I find anyone I can get along with or tolerate for any length of time. Thank you in advance.