There are 11 US Post Offices in Jackson County serving a total of 43,180 residents equating to 3,925 residents per post office. It's estimated that approximately 68,920 packages are handled across the 11 county post offices annually. Jackson County is a county located in the U.S. state of Florida. As of the 2010 census, the population was 49,746. Its county seat is Marianna."