Mo. Rev. Stat. § 1.190: Notices, how served.

Whenever any of the statutes of this state require or imply that a notice shall be given to any person concerning or affecting any right, property, claim, duty, matter or thing of any character or nature, unless the statutes expressly direct a different method of service, the delivery of a true copy of the notice to the person intended to be notified, or the leaving of a copy at his usual place of abode with some member of his family over the age of fifteen years, constitutes a valid and sufficient service of the notice.