The American University of Beirut (AUB) was founded in 1866 and has a worldwide reputation for academic excellence. AUB serves more than 7,500 students and employs more than 3,500 faculty and staff.

In the early days of the Internet, AUB adopted the open-source Exim message transfer agent as its e-mail system, running under the Red Hat Linux operating system. As commercial messaging systems were introduced and updated to be evermore sophisticated, faculty and staff wanted features such as shared calendars, Web mail, and mobile mail access that were not easy to implement with Exim. Faculty and hospital staff compensated for the deficiencies by bringing in a variety of third-party solutions to fill their needs, but these presented security, accessibility, and maintenance issues.

In 2006, AUB decided to standardize on Active Directory® Domain Services as its primary authentication platform across numerous and diverse services and applications. And then in late 2007, AUB piloted Microsoft Exchange Server 2007 Enterprise Edition with Service Pack 1 (SP1) in a two-server cluster running the Windows Server 2003 operating system. The IT staff uses a single-cluster-copy design to provide instant fail-over capability from the primary to the backup server. The IT staff estimates that each mail server can handle 250 concurrent users, so the current cluster will accommodate 4,000 mailboxes. The university will gradually migrate user mailboxes from Exim to Exchange Server.