Us Government--postal Service, Holcomb Monroe Center, IL 61052 Phone : (815) 393-4255 Business Category Government Offices-Federal Government Offices & Public Schools Post Office - Holcomb 105 W Main St Holcomb, IL 61043 Phone : (815) 393-4255 Post Office - Holcomb Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (815) 393-4809