Business email has become so important that many organizations want to have the highest possible availability. This Essential Guide describes what "high availability" really means, then discusses different strategies that you can use to improve your systems' availability and resiliency. Covered topics include backup and restore technology, clustering, and data replication; you'll learn how these technologies work, and -- more importantly -- what they don't protect you against. By reading this Essential Guide, you'll be prepared to choose appropriate solutions to protect your messaging data at the lowest cost and with the highest reliability.a