There are 7 US Post Offices in Effingham County serving a total of 55,937 residents equating to 7,991 residents per post office. It's estimated that approximately 89,282 packages are handled across the 7 county post offices annually. Effingham County is a county located in the U.S. state of Georgia. As of the 2010 census, the population was 52,250. The seat is Springfield. Effingham County is included in the Savannah, GA Metropolitan Statistical Area. In 2008, Effingham County was ranked as the sixth fastest-growing midsize county in the nation from 2000 to 2007 by the U.S. Census Bureau. The county had a 35.1% growth rate over that period."