Mo. Rev. Stat. § 357.110: Proxies, how voted.

At any regularly called general or special meeting of shareholders for the purpose of electing directors, a written vote signed by and received by mail or messenger from any absent shareholders shall be accepted as the vote of such absentee. This rule shall apply also to any such written vote of an absentee at any regularly called general or special meeting of shareholders for the purpose of determining the business policies of such association.