We do require our sellers to use a valid e-mail address and phone number when posting ads on our website. However, because of the increasing concern of spam and counterfeit check scammers, we do not make e-mail addresses visible on our website. Potential buyers must use a contact form to contact a seller through our system. We recommend using a secondary e-mail address for any type of public forum such as ours, and keeping your primary e-mail address private. There are many free e-mail services available on the web, including Yahoo, Hotmail, Gmail, and others.