An electronic document communication system, comprising: a plurality of transceiving entities that transmit and receive a message based on an electronic mailing address and communicate the electronic document through a communication messaging server that issues and manages a communication certificate for message transmission/reception; a communication hub that registers/manages the electronic mailing address of the transceiving entities, sets an electronic document communication route between the transceiving entities, provides a standard form of the electronic document to the transceiving entities, transmits the message by proxy when an error occurs in the process of communication the electronic document between the transceiving entities and issues a communication certificate; and a reliable third party storing institution that receives and stores the communication certificate, wherein the electronic mailing address is the certified electronic address which is information for discriminating the transceiving entities and is registered and managed by a registered institution, wherein the transceiving entities support the exchange of the electronic documents and the reading of the electronic document, wherein the communication hub includes an externally connected gateway server for connection with an external system, wherein there are a plurality of users, and wherein the communication messaging server authenticates each user, creates the message, inquires a message list and reads the detailed contents of the message list, and connects a communication client application, wherein the communication messaging server stores the transceiving message in a mailbox so as to include status information for every user, stores a message transceiving record in a medium that is not allowed to edit and delete the message transceiving record for a predetermined period of time, issues the communication certificate for the message transmission/reception to request the third party storing institution to store the communication certificate, allows the transceiving entities to use function of registering, searching, editing, and deleting the electronic mailing address in connection with the address directory server of the communication hub, and moves messages which are stored for a predetermined period of time or longer to an external storage device to be stored. a plurality of transceiving entities that transmit and receive a message based on an electronic mailing address and communicate the electronic document through a communication messaging server that issues and manages a communication certificate for message transmission/reception; a communication hub that registers/manages the electronic mailing address of the transceiving entities, sets an electronic document communication route between the transceiving entities, provides a standard form of the electronic document to the transceiving entities, transmits the message by proxy when an error occurs in the process of communication the electronic document between the transceiving entities and issues a communication certificate; and a reliable third party storing institution that receives and stores the communication certificate,