Anyone who is not a party to the action and is not less than 18 years of age may serve process. A sheriff of the county in which the defendant resides or is found may also serve process upon the written request of the petitioner or his or her attorney.

If process is being served by a sheriff, the sheriff marks all summons with the date of the receipt by him, and within thirty days of the date of such receipt, he or she shall return the summons to the clerk of the court.

The divorce papers may be served by mailing them by first-class mail, postage prepaid to the person to be served, together with two copies of a notice and acknowledgment. If no acknowledgment of service under this subdivision of this rule is received by the sender within 20 days after the date of mailing, service of such summons and complaint may be made in any other manner permitted by law.

Unless good cause is shown for not doing so, the court shall order the payment of the costs of personal service paid by the person served if such person does not complete and return within 20 days after mailing the notice and acknowledgment of receipt of summons.

The notice and acknowledgment of receipt of summons and complaint shall be executed under oath or affirmation.

When the defendant cannot be found after a diligent search, and with the approval of the court, the defendant may be served by publication.

The publication of the summons is made once in each week during three successive weeks in a public newspaper of the county where the complaint or petition, account, cause or other proceeding is pending. Where there is no newspaper, the notice is posted at the courthouse door of the county and published as above provided in a public newspaper in an adjoining county or at the seat of government of the state. Upon completion of publication, proof of the prescribed publication is filed in the papers in the cause. The defendant has 30 days from the date of first publication to defend. Where the post office address of a defendant is given, the street address, if any, shall also be stated unless the complaint, petition, or affidavit above mentioned, states that after diligent search and inquiry said street address could not be ascertained.

When the address is stated, the clerk sends copies of the divorce papers to the defendant, and this is evidence of the summons having been mailed to him or her.

A summons may be served on a person outside this state by sending the divorce papers to the respondent by certified mail, return receipt requested. The envelope is marked "restricted delivery." Service by this method is complete as of the date of delivery as evidenced by the return receipt or by the returned envelope marked "Refused."