Mo. Rev. Stat. § 36.380
An appointing authority may dismiss for cause any regular employee in his or her division when he or she considers that such action is required in the interests of efficient administration and that the good of the service will be served thereby. No dismissal of a regular employee shall take effect unless, prior to the effective date thereof, the appointing authority gives to such employee a written statement notifying the employee of the decision and setting forth in substance the reason therefor. When it is not practicable to give the notice of dismissal to an employee in person, it may be sent to the employee by certified or registered mail, return receipt requested, at his or her last mailing address as shown in the personnel records of the appointing authority. Proof of refusal of the employee to accept delivery or the inability of postal authorities to deliver such mail shall be accepted as evidence that the required notice of dismissal has been given. Any regular employee who is dismissed shall have the right to appeal to the administrative hearing commission as provided under section 36.390.
§ 36.380, RSMo