An electronic mail-facsimile communication system, an electronic mail-facsimile communication method, and a recording medium on which a program code is recorded for performing a method that allow a facsimile transmission image to be previewed is presented herein. It includes a system for faxing electronic mail over a network includes a client connected to the network and a gateway unit for transmitting a facsimile transmission image to a facsimile machine over a telephone line. The gateway unit converts an e-mail sent from the client into a facsimile transmission image, and creates electronic mail containing the facsimile transmission image to return the electronic mail to the client before sending the electronic mail to the facsimile machine.