Tennessee Code Title 56. Insurance § 56-2-505

(a) Any act of entering into a contract of insurance as an insurer or transacting insurance business in this state, as set forth in § 56-2-107, by an unauthorized foreign or alien company, is equivalent to and constitutes an appointment by the company of the secretary of state to be its true and lawful attorney upon whom may be served all lawful process in any action or proceeding against it:

(b) The performance of any of the acts enumerated in § 56-2-107 is signification of the company's agreement that any such process against it that is so served is of the same legal force and validity as if served upon the company.