Mo. Rev. Stat. § 492.180: Notice, how served on party or attorney.

Such notice, when served on the adverse party or his attorney, shall be:

(1) By delivering to him a copy thereof;

(2) By leaving a copy at his usual place of abode, with some member of his family above the age of fifteen years, or at his office with some clerk above the age of fifteen years; and

(3) In case the adverse party is a railroad or other corporation, such notice may be served by delivering a copy thereof to any station agent of such railroad corporation, or to any local agent of such other corporation, at his office in the county in which the suit was brought or is pending.