A distributed and expansible architecture for providing message communication service to nodes, which are typically shelters, in a wide disaster-affected area is presented. The large disaster-affected area is divided into a number of sub-areas, to each of which a pair of electric and unmanned aerial vehicles (EVs and UAVs) is assigned. Message files are sent and received through a wireless link between each node and the UAV flying over the node. They are also carried by this UAV (end-to-end-transfer) or carried/relayed by multiple UAVs (relay transfer) from/to the center station in the area. For simple square area modeling, sub-area formation methods such as time-uniform, space-uniform, and hybrid-uniform divisions are established for end-to-end transfer. The relay can be performed synchronously or asynchronously in relay transfer. Several observations are made through numerical examples.