1.  Field of the Invention The present invention generally relates to a diagnosis method for a device connected to a main server.  More particularly, the present invention relates to a diagnosis method for a device by use of an electronic mail message. 
2.  Description of the Related Art
A network system consists of a main server and a plurality of devices.  The main server controls and manages the plurality of the devices, as shown in FIG.  1. 
Referring to FIG.  1, a network system includes a plurality of devices 102 through 106.  The devices may be a printer, a scanner, a facsimile machine and the like.  The following describes a method by which a main server 100 diagnoses the devices 102 through 106 in the network system, especially when a first device 102 operates abnormally. 
The first device 102 having an abnormal operation notifies the main server 100 of the abnormality.  The main server 100 selects one of diagnosis programs stored therein.  The main server 100 selects a diagnosis program relating to the notified information among the diagnosis programs. 
The main server 100 sends the selected diagnosis program to the first device 102 notifying the abnormal operation.  The first device 102 diagnoses the abnormal operation by use of the received diagnosis program and acquires a diagnosis result.  The first device 102 sends the diagnosis result to the main server 100. 
As explained above, the main server 100 transfers a diagnosis program capable of removing the abnormal operation.  The greater the number of devices in the network, the greater the number of messages delivered to the main server 100.  In this situation, the main server 100 has to transfer diagnosis programs to all of the devices indicating the abnormal operation.  Furthermore, the main server needs to select and transfer a suitable diagnosis program relating to the indicated abnormal operation. 
Accordingly, as the number of the devices in the network increases, the load on the main server 100 also increases, which requires a solution to reduce the load on the main server 100.