Communication processing system, group message processing method, communication processing apparatus, and control method and control program of communication processing apparatus

A non-transitory computer readable medium storing a program of controlling a communication processing apparatus for causing a computer to execute a method, comprising:

• holding, in a holder, identifiers of a plurality of devices included in a device group as a target of a group messaging requested from an application;
• acquiring an unreached-device list created by excluding identifiers of devices which a group message has reached from the identifiers held in the holder, based on responses to delivery of the group message;
• and
• delivering a message based on the group messaging to devices having identifiers included in the unreached-device list.

A group message processing method comprising:

• holding, in a holder, identifiers of a plurality of devices included in a device group as a target of a group messaging requested from an application;
• acquiring a plurality of devices which a group message has reached based on responses of devices to delivery of the group message, and generating an unreached-device list by excluding the identifiers of the plurality of reached devices from the identifiers held in the holder;
• and
• delivering a message based on the group messaging to devices having identifiers included in the unreached-device list.