As of DME server 4.2, DME supports the Microsoft Push Notification Service (MPNS). On Windows Phone devices, MPNS is supported by DME in clients 4.1.1 and above.
Minimum requirements for running MPNS:
DME Server: At least 4.2
DME Client: At least 4.1.1
Windows Phone: At least 8
Other: A Windows Live account
MPNS (sometimes known as Microsoft Push) is a service that lets DME send notification data from the DME server to Windows Phone devices. For MPNS to work on a device, the user must have a Windows Live account. Users typically have a Windows Live account; it is required for downloading apps to the device.
MPNS is run by the Windows Phone operating system. Thus it runs all the time, and not only while DME is running. This way, you will receive notifications about for instance new e-mails, even if DME is not running. Tapping the notification will open DME, start the synchronization process, and open the new e-mail.
With DME client 4.2 and above, the DME tile at the Home screen will show an icon if new e-mails or meeting invitations have arrived since the user last opened DME.
If DME is running already when the MPNS push arrives, DME will start a sync process immediately.