Abstract: A method for composing and transmitting, and method for receiving and looking-up an electronic message which enable an operator to simply interact with a computer provided with a visualiser or a display, so as to enable electronic documents visualizable by informatic programs not included in the computer to be visualized, thereby allowing a noticeable reduction of any infomatic virus diffusion. Instruments needed to perform such methods and the apparatus by which the methods are performed are also disclosed.