Mo. Rev. Stat. § 513.225: Notice to be given defendant in execution if a resident of the state, when.

When real estate, situated in a different county from that in which the defendant in the execution owning such real estate resides, is sought to be sold under an execution in favor of the plaintiff therein, it shall be the duty of the plaintiff to cause a notice, in writing, to be served on the defendant or defendants owning the real estate, if residing in the state, stating the fact of the issuing of the same, how or to what county directed, and to what term of the court said execution is returnable.