Oregon Certificate of Service by Mail is a document used to provide proof that documents have been sent by mail. The certificate includes the date of mailing, the name and address of the recipient, the type of document sent, and the method of delivery. It is a sworn statement issued by an authorized officer of the Oregon court system to verify that documents have been properly served. There are two types of Oregon Certificate of Service by Mail: the Notice of Service Certificate and the Waiver of Service Certificate. The Notice of Service Certificate is used to notify the recipient of the documents being served, while the Waiver of Service Certificate is used when the recipient waives service. Both certificates must be signed by an authorized officer of the court in order for them to be valid.