As of DME server 4.1, DME supports the Google Cloud Messaging (GCM) notification service. On the Android devices, GCM is supported by DME in clients 4.1 and above, and by Android 2.2 and above.
Minimum requirements for running GCM:
DME Server: At least 4.1
DME Client: At least 4.1
Android: At least 2.2
Other: A Google account
GCM (sometimes known as Google Push) is a service that lets DME send notification data from the DME server to Android devices. For GCM to work on a device, the user must have a Google account. Users typically have a Google account; on Android 4.x, a Google account is required to use the device.
GCM is a service which is run by the Android 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.
If DME is running already when the GCM push arrives, DME will start a sync process immediately.
DME still supports the legacy Network Push. However, the Network Push functionality is deprecated and will be removed from DME clients and the server in the future.