To provide a communication terminal and a repeater that cause no confusion with respect to image data received by a receiver side on the occur rence of an error when faxing the image data through the use of an Internet mail utilizing type facsimile transmission system.

A main control section 1 of a facsimile machine 20 transmits an IRA (Internet Routing Address) signal or an NSS(Non-Standard function Setting) signal that is protocol signal including an electronic mail address of a destination to the repeater 60 together with image data consisting of a plurality of pages (steps S11 and S14 in Figure 6), interrupts a public telephone line L1 of a pubic telephone network 50 (step S20B) when faxing of all the pages is not completed (NO in step S19) and re-transmits the image data from the first page and the protocol signal including the electronic mail address of the destination to the repeater 60 (processing of step S9 and succeeding steps).