A non-transitory computer readable medium includes instructions which, when executed by one or more hardware processors, causes performance of operations. The operations include receiving, by a network device from a first user device, a first message addressed to a second user device and identifying a first user role associated with the first user device and a second user role associated with the second user device. The operations further include determining whether a set of predefined user role relationships authorizes a communication between user devices having the first user role and user devices having the second user role. In response to determining that the set of predefined user role relationships do not authorize the communication between user devices having the first user role and user devices having the second user role, the operations refrain forwarding the first message from the first user device to the second user device.