A method of operating a router for enabling communication between a plurality of host services and a mobile device is described. The method includes receiving notification messages from a host service of the plurality of host services, where the plurality of host services support a plurality of message types. Each notification message has contents indicating a destination mobile device and a data message for the destination mobile device stored on the host service. The data message has a message type corresponding to one of the plurality of message types. The method further includes determining whether a first active service session with the destination mobile device exists and, if the first active service session exists, then sending the notification message to the destination mobile device for subsequent retrieval of the indicated data message stored on the host service using a second active service session between the destination mobile device and the host service. The method further includes, if no active service session exists, then holding the notification message until a new active session is detected, and upon detecting the new active session, sending the notification message to the destination mobile device for subsequent retrieval of the indicated data message stored on the host service using a second active service session between the destination mobile device and the host service.