Tennessee Code Title 56. Insurance § 56-2-506

(a) Service of process shall be made by delivering and leaving with the secretary of state two (2) copies of the process.

(b) The secretary of state shall forthwith mail by registered mail one (1) of the copies of the process to the company at its last known principal place of business, and shall keep a record of all process so served upon the secretary of state.

(c) The service shall be sufficient service upon the company; provided, that notice of the service and a copy of the process are, within ten (10) days thereafter, sent by registered mail by or on behalf of the commissioner to the company at its last known principal place of business; and provided, further, that the receipt by the secretary of state and an affidavit of compliance with this section by or on behalf of the commissioner are filed with the clerk of the court in which the action or proceeding is pending on or before the return date of the process or within any further time that the court allows.