Ind. Code § 27-4-5-4
(c) The secretary of state shall forthwith forward by certified mail one (1) of the copies of such process or such notice, order, pleading, or process in proceedings before the commissioner to the defendant in such court proceeding or to whom the notice, order, pleading, or process in such administrative proceeding is addressed or directed at its last known principal place of business and shall keep a record of all process so served on him which shall show the day and hour of service. Such service is sufficient, provided:
(e) Nothing in this section shall limit or affect the right to serve any process, notice, order, or demand upon any person or insurer in any other manner permitted by law.
Formerly: Acts 1969, c.194, s.4; Acts 1971, P.L.1, SEC.10. As amended by P.L.252-1985, SEC.167.