Service of process within the state, except as otherwise provided by law, may be made by the sheriff or any person over the age of 18 years who is not a party to the action.

The divorce papers in Missouri are the summons and petition.

Personal service within Missouri is made by delivering a copy of the divorce papers personally to the defendant or by leaving a copy of the papers at the individual's house or usual place of abode with some person of his or her family over the age of 15, or by delivering a copy of the papers to an agent authorized by appointment or required by law to receive service of process.

Service of the summons and petition upon a resident or nonresident defendant may be made by mailing the papers by first class mail, to the defendant served, together with two copies of a notice and acknowledgment conforming substantially to Civil Procedure Form 4B or Civil Procedure Form 4C, and a return envelope, postage prepaid, addressed to the sender.