Missouri Revised Statutes Title XXIV. Business and Financial Institutions § 375.266. Service of process valid, when

(1) Soliciting insurance, or

(2) Making, issuing or delivering any contract of insurance, or

(3) Collecting or receiving any premium, membership fee, assessment or other consideration for insurance; and if a copy of the summons issued, with a copy of the officer's return thereon, together with a copy of plaintiff's petition thereto attached, are sent within ten days thereafter by certified mail, with return receipt requested, by the plaintiff or plaintiff's attorney to the defendant at the last known principal place of business of the defendant, and the return receipt and the affidavit of plaintiff or plaintiff's attorney showing compliance therewith are filed with the clerk of the court in which the action is pending on or before the date the defendant is required to appear and defend the cause of action.