There are 3 US Post Offices in Smith County serving a total of 12,905 residents equating to 4,302 residents per post office. It's estimated that approximately 20,598 packages are handled across the 3 county post offices annually. Smith County is a county located in the U.S. state of Mississippi. As of the 2010 census, the population was 16,491. Its county seat is Raleigh. Smith County is a prohibition or dry county."