United States Government--post Offices, Jacksonville, For Zip Code Information Jacksonville, MO 65260 Phone : (660) 295-4243 Business Category Government Offices-Federal Post Offices Government Offices & Public Schools Post Office - Jacksonville 124 W Randolph St Jacksonville, MO 65260 Phone : (660) 295-4243 Post Office - Jacksonville Business Category Government Offices-Federal Post Offices Government Offices & Public Schools Toll-Free           (800) ASK-USPS