Let him know that you really enjoy talking to him. Laugh at his jokes. Tell him how funny he is, and that you like a man with a sense of humor. Whatever you say, make sure it's authentic. Let him know that you like his emails and that you also like to be courted in person.
Men like to be helpful.
In fact, most men live to help women, if only women would let them. I'm sure you can think of something. Then, next time he calls you, tell him that you would like his help with whatever. When he comes over, be your feminine self. Be open, vulnerable, receptive and charming.