Oklahoma Notice and Certificate of Mailing is a document used for service of process in the State of Oklahoma. It is used to provide legal notice to a defendant in civil or criminal proceedings. This document is filed with the court in order to prove that the defendant was served with a summons or other court documents. It is also used to provide notice to other parties involved in a legal matter. There are two types of Oklahoma Notice and Certificate of Mailing: Certified Mail and General Delivery. Certified Mail is used for sending documents to the defendant, which requires a signature upon delivery. General Delivery is used for mailing documents to the defendant with no signature required. Both types of Notice and Certificate of Mailing must be properly completed and filed with the court in order to be considered valid.