If the buyer does not have a "confirmed" address, it is really not a big deal. If the buyer files a claim with Paypal that they never received the item, and it was shipped to an unconfirmed address, Paypal might not mediate in your favor. Get the buyer to send you an email stating where to ship, then have a way to track the shipment and confirm delivery. That email and tracking record will help with any future mediation (should it become necessary).