NASHVILLE, Tenn.--(BUSINESS WIRE)--Emma, a provider of best-in-class email marketing software and services, today announces Marketing United, a three-day conference for marketers to come together to share successes and challenges, learn from industry leaders and network in downtown Nashville, one of America’s fastest-growing cities. The event will be held April 29 through May 1, 2015 at various downtown locations, with pre-conference programming and a closing party on the Emma campus. The confe