There are 2 US Post Offices in Clay County serving a total of 2,932 residents equating to 1,466 residents per post office. It's estimated that approximately 4,680 packages are handled across the 2 county post offices annually. Clay County is a county located in the U.S. state of Georgia. As of the 2010 census, the population was 3,183, making it the fifth-least populous county in Georgia. The county seat is Fort Gaines."