All I get off Craigs List are emails such as: “Are the items still for sale? Send me your e-mail address so I can make immediate payment for your price”
Those are spammers. They can only respond to your ad, but if you respond then they have your email address. I only respond to people who mention specifically what you are selling, and at least include a name if not a phone number. If you don’t get any legitimate responses either you are asking too much, or selling something nobody wants.