The Oregon Certificate of Mailing is a form used to certify that the sender has mailed documents out of the state of Oregon. It is a document that is issued by the United States Postal Service (USPS) in Oregon and provides proof that the documents were sent by mail. The Oregon Certificate of Mailing guarantees that the documents were sent from the specified address in Oregon and that the documents were received by the intended recipient. There are three types of Oregon Certificate of Mailing: Standard Certificate of Mailing, Registered Certificate of Mailing, and Certified Certificate of Mailing. The Standard Certificate of Mailing is the most basic type of certificate and is issued without any guarantee that the documents were received by the recipient. The Registered Certificate of Mailing is a more secure form of certificate and provides a tracking number for the documents, allowing the sender to track the delivery of the documents. The Certified Certificate of Mailing is the most secure form of certificate and provides the sender with proof that the documents were received by the recipient.