Oregon Revised Statutes Property Rights and Transactions § 105.158

(a) Is a resident of the State of Oregon;

(b) Is not the plaintiff, a relative of the plaintiff or an agent of the plaintiff for purposes of management of the premises;

(c) Is a person regularly employed in the business of serving process; and

(d) Charges a fee no greater than that set by ORS 21.300 (1)(a) for service of the notice of restitution.

(a) The sheriff or process server shall mail a copy of the notice of restitution by first class mail to the defendant at the premises; and

(b) The sheriff or process server shall serve the notice of restitution at the premises by personal delivery to the defendant or, if the defendant is not available for service, by attaching a copy of the notice in a secure manner to the main entrance to that portion of the premises of which the defendant has possession.