The present invention is a data network system (110) and method for responding to a communication message with a canned reply by a target user of a target client device (one of 102-108). The data network system comprises a messaging server (112) and a messaging proxy (120) coupled to the messaging server. Initially, the target client device or, more particularly, the target user, configures one or more canned replies for the system. The messaging proxy then receives (204, 304, 404) a communication message from an originating client device (another one of 102-108) and retrieves (206, 306, 406) configuration data of the target client device. Next, the messaging proxy determines (208, 308, 408) whether the target client device is available for interactive communication with the originating client device based on the configuration data. If the target client device is available for interactive communication with the originating client device, then the messaging proxy routes (210, 310, 410) the communication message to the target client device. Otherwise, if the target client device is not available for interactive communication with the originating client device, then the system withholds (230, 330, 430) the communication message from the target client device and sends (230, 330, 430) the canned reply to the originating client device.