Tennessee Code Title 40. Criminal Procedure § 40-13-303

(a) If served by an officer not of the county to which it is returnable, the return may be made by depositing the capias in any post office, sealed up, directed to the clerk of the court at the courthouse of the originating county with the title of the case endorsed on the envelope and the postage paid.

(b) The undertaking of bail, if any, shall also be returned with each capias.

(c) The postage paid upon process sent by mail shall constitute a part of the bill of costs.

(d) The clerk of the court to whom packages are addressed according to this section shall take them from the post office and file them without delay.