This document discusses Exchange Active Synchronization (EAS) and its advantages over Active Synchronization (AS). EAS allows synchronization of email, calendars, contacts and other data between a mobile device and email server, supporting features that AS does not such as full contact and calendar synchronization. The document outlines strengths of EAS, differences between EAS and AS, solutions EAS provides for issues with older Exchange servers, new features and policies introduced in updated EAS versions, when and why EAS should be used, and overall benefits of EAS.