The on-premise installation of the AirWatch Secure Email Gateway acts as a proxy between devices and email infrastructure. The PowerShell model integrates with email infrastructure using Windows PowerShell APIs and secure cloud integration via AirWatch Enterprise Integration Service (EIS). Both feature the ability to:
•Configure email over-the-air
•Block unmanaged devices
•Discover existing unmanaged devices
•Require device encryption
•Prevent compromised devices
•Block mail client, user, device model or OS
•Integrate or revoke certificates (Exchange 2003/2007 for SEG and Exchange 2010 for EIS)
Differences
Proxy
•Proxy email traffic through AirWatch Secure Email Gateway (SEG) server
•Deploy scalable, highly available and redundant server architecture
•Support Exchange 2007 and 2003, Lotus Domino with Lotus Notes, Novell Groupwise 8.0 (with EAS), any other EAS infrastructure
PowerShell
•Native AirWatch integration for email access control
•Leverage existing email environments (no gateway)
•Support Exchange 2010, Office 365/BPOS infrastructures
Let me know if that is helpful or if I can point you toward any additional information or an internal resource at AirWatch.