Mo. Rev. Stat. § 390.141: Orders and decision of division of motor carrier and railroad safety to be written — how served.

The orders and decisions of the division on the matters covered by the provisions of this chapter shall be reduced to writing and a copy thereof, duly certified, shall be served on the motor carrier affected thereby through the United States mail, and such order and decision shall become operative and effective within thirty days after such service, unless otherwise ordered by the division, and such motor carrier shall carry the provisions of said order into effect unless said order is enjoined or set aside in a court of proper jurisdiction.