"If you were adversely affected by this decision, you may appeal to the administrative hearing commission. To appeal, you must file a petition with the administrative hearing commission within thirty days after the date this decision was delivered. If your petition is sent by registered or certified mail, it will be deemed filed on the date it is mailed; if it is sent by any method other than registered mail, it will be deemed filed on the date it is received by the commission.".
§ 621.275, RSMo