1. A messaging system for conveying messages between a host server and a client that is part of a wireless communication network including a plurality of wireless clients having a messaging service to convey messages wirelessly therebetween using a messaging service server, each wireless client having a network identifying number associated therewith to uniquely identify the client within the wireless communication network, and each message comprising a message packet including the address of an intended recipient of the message packet and the address of the sender of the message; the messaging system comprising: a host server to which a plurality of clients may be selectively connected via a computer network to convey messages therebetween, each of the clients having a client identifying number associated therewith to uniquely identify the client to the host server; the host server and the messaging service server being interconnected by a further computer network to provide for communications therebetween; one of the clients of the host server being a wireless client and having the client identifying number corresponding to the network identifying number thereof; the host server having an access code to uniquely identify the host server to the messaging service server and a unique identification number ascribed to: (a) a prescribed action performed by the host server, and (b) an entity that is the subject of the prescribed action; wherein messages sent between the host server and the one client in connection with a particular prescribed action and entity include: (i) a combination of the access code and the unique identification number ascribed to the particular action and entity as the address of the host server in message packets sent to or from the one client as the sender or the intended recipient, respectively, and (ii) the network identifying number as the address of the one client in message packets sent to or from the host server as the sender or the intended recipient, respectively; and wherein the messaging service server uses the access code in the address of the intended recipient or the sender to recognise messages sent to or received from the host server and rout messages accordingly.