Mont. Code Ann. § 72-3-511

By accepting appointment, a personal representative submits personally to the jurisdiction of the court in any proceeding relating to the estate that may be instituted by any interested person. Notice of any proceeding must be delivered to the personal representative or mailed to the personal representative by ordinary first-class mail at the address as listed in the application or petition for appointment or as reported to the court and to the personal representative's address as then known to the petitioner.