Washington Revised Code Title 26. Domestic Relations § 26.27.081. Notice to persons outside state

(1) Notice required for the exercise of jurisdiction when a person is outside this state may be given in a manner prescribed for service of process by the law of the state in which the service is made or given in a manner reasonably calculated to give actual notice, and may be made in any of the following ways:

(2) Proof of service outside this state may be made:

If service is made by mail, proof may be a receipt signed by the addressee or other evidence of delivery to the addressee.

(3) Notice is not required for the exercise of jurisdiction with respect to a person who submits to the jurisdiction of the court.