I've already signed up for a new account at
http://www.heatware.com, but if I sell something to someone, they paid me, and I shipped it, how do I email them to tell them to give me feedback about the item? Can I also use this site for things I sell on CraigsList, where the buyer comes to my house, pays me, and then I email him to give me feedback on HeatWare?
It doesn't seem that intuitive.