There are many reasons that a package may be returned to them as undeliverable, here are some of them: Incorrect Address. If the address is incorrect or outdated, the package is typically returned to them by the carrier or the unintended recipient. They will then attempt to contact you for an updated address. The customer is subject to an additional shipping fee. Carrier Does Not Deliver to the Address. The U.S. Postal Service does not deliver to some addresses. If you also have a PO Box address, it's best to use that address if USPS does not deliver to your home address. All orders with a "PO BOX" in the address are shipped via U.S. Mail. Failed Delivery Attempts. Most of their carriers make three attempts to deliver a package. After three attempts, the package will be returned to them. Refused by Recipient. If a package is refused by the recipient, they will be liable for all additional shipping charges and fees to have it abandoned or returned.