U S Government--post Offices, White Oak Holcomb, MO 63852 Phone : (573) 888-0700 Business Category Post Offices Government Offices & Public Schools Post Office - Whiteoak 3 Main St Whiteoak, MO 63880 Phone : (573) 888-0700 Post Office - Whiteoak Business Category Post Offices Toll-Free           (800) ASK-USPS