If a representative is or becomes a nonresident of this State, the representative shall file in the court in which the estate is pending a designation of a resident agent to accept service of process, notice or demand required or permitted by law to be served upon the representative. If the representative fails to do so, the clerk of the court is constituted as agent of the representative upon whom the process, notice or demand may be served. If service is made upon the clerk of the court, the clerk of the court shall mail a copy of the process, notice or demand to the representative at the representative’s last known post office address and to the representative’s attorney of record.