U S Government--post Offices, Kewanee New Madrid, MO 63869 Phone : (573) 748-2260 Business Category Post Offices Government Offices & Public Schools Post Office - Kewanee 517 State Hwy W Kewanee, MO 63860 Phone : (573) 748-2260 Post Office - Kewanee Business Category Post Offices Toll-Free           (800) ASK-USPS