Tenn. Code Ann. § 56-2-107: Acts of unauthorized insurers constituting doing business in state

Any of the following acts in this state, effected by mail or otherwise by an unauthorized insurer, are included among those deemed to constitute transacting insurance business in this state:

(1) The issuance or delivery of contracts of insurance to residents of this state;

(2) The solicitation of applications for contracts of insurance;

(3) The collection of premiums, membership fees, assessments or other considerations for contracts of insurance; or

(4) The transaction of matters subsequent to the execution of contracts of insurance and arising out of them.