deal it professionally if you are not interested

Do whatever he wants you to do as far as it is work-related. cc your boss. If you are interested in a romantic way, give him some hints, if he is available.
I don't think he is romantically interested. email can be seen by too many people, like his secretory. Unless he is crazy, this is not the right way for a romantic relationship. He probably just want to get first-hand information directly from you, instead of processed info from your boss' boss' boss' boss etc.