The best way to handle this is really to do nothing. When the person responded to the CL ad, they didn't know your email address. It wasn't visible in Craig's List and they clicked on a link provided by CL. If you respond (even to give them a piece of your mind and to say "ARE YOU KIDDING, I am no dummy") they will then have your email address.
whenever you are selling anything, simply put in your ad,
Local buyers only; cash only; will not ship. Ignore the responses that don't comply to this.