A system for communicating an alert message to a plurality of recipients, each recipient being associated with a respective communications device, each device being a respective one of a plurality of device types, each device having a respective address, the system comprising: a dispatch module for receiving the alert message, message subscriber data, and device identification criteria, the message subscriber data received from a database identifying registered recipients and addresses of their associated communications devices, wherein the dispatch module is for compiling a list of the recipients based in part on the message subscriber data, and wherein the dispatch module is for communicating with a communications node accessible to the system for querying or polling said communications node and, responsive thereto, receiving directly from the communications node an identification of communications devices currently accessible via that communications node based on the device identification criteria, wherein the device identification criteria specify a logical or physical proximity of the device to the communications node or a specified location, wherein the dispatch module is further for compiling the list of the recipients based in part on the identification received from the communications node, wherein the communications node is a network access point which is wired or wireless, and the identification received from the communication node includes an address of at least one communications device of an unregistered recipient; a delivery module for receiving from the dispatch module the message and the list of the recipients comprising registered recipients and at least one unregistered recipient, the delivery module being further for receiving the device addresses based on the list of the recipients, the delivery module being further for communicating the message to the devices specified by the list of recipients comprising registered recipients and at least one unregistered recipient, the delivery module having for each device type a corresponding delivery sub-module for communicating the message to the devices of that device type; and the database for receiving and storing the message, the list of the recipients comprising registered recipients and at least one unregistered recipient, the device types, and the device addresses including the message subscriber data comprising identifiers of the registered recipients and their associated device addresses and device types. a dispatch module for receiving the alert message, message subscriber data, and device identification criteria, the message subscriber data received from a database identifying registered recipients and addresses of their associated communications devices, wherein the dispatch module is for compiling a list of the recipients based in part on the message subscriber data, and wherein the dispatch module is for communicating with a communications node accessible to the system for querying or polling said communications node and, responsive thereto, receiving directly from the communications node an identification of communications devices currently accessible via that communications node based on the device identification criteria, wherein the device identification criteria specify a logical or physical proximity of the device to the communications node or a specified location, wherein the dispatch module is further for compiling the list of the recipients based in part on the identification received from the communications node, wherein the communications node is a network access point which is wired or wireless, and the identification received from the communication node includes an address of at least one communications device of an unregistered recipient; a delivery module for receiving from the dispatch module the message and the list of the recipients comprising registered recipients and at least one unregistered recipient, the delivery module being further for receiving the device addresses based on the list of the recipients, the delivery module being further for communicating the message to the devices specified by the list of recipients comprising registered recipients and at least one unregistered recipient, the delivery module having for each device type a corresponding delivery sub-module for communicating the message to the devices of that device type; and the database for receiving and storing the message, the list of the recipients comprising registered recipients and at least one unregistered recipient, the device types, and the device addresses including the message subscriber data comprising identifiers of the registered recipients and their associated device addresses and device types.