To disconnect an EAS device from management by the Exchange Mobile Device Server:
In the Mobile Device Management folder in the console tree, select the Mobile devices subfolder.
The folder workspace displays a list of managed mobile devices.
In the workspace, filter EAS devices by clicking the Exchange ActiveSync (EAS) link.
Select the mobile device that you want to disconnect from management by the Exchange Mobile Device Server.
In the context menu of the mobile device, select Delete.
The EAS device is marked for removal with a red cross icon. The mobile device is removed from the list of managed devices after it is removed from the Exchange ActiveSync Server database. To do so, the administrator must remove the user account on the Microsoft Exchange server.