BlackBerry Enterprise Server (BES) is a middleware program that allows BlackBerry devices to access corporate messaging and collaboration software such as Microsoft Exchange, Lotus Domino and Novell GroupWise. The middleware synchronizes messaging content between enterprise servers and Research in Motion Blackberry smartphones.
BES is generally deployed as a series of individual Windows services. Each service handles unique messaging elements such as attachments, collaboration, device status, messaging, master data service (MDS) connections, policies and synchronization. Services can be installed and managed individually, allowing an organization can deploy the level of BlackBerry support and control that best suits their requirements. A messaging administrator, sometimes referred to as a BES Administrator, is typically tasked with supporting the BES services.
In 2011, RIM announced plans for a upgrade that will allow administrators to use BES to to manage and support Apple and Android mobile devices.
A free version of BES (BES Express) provides much of the functionality found in the full version of BES.