In recent years, a network facsimile device for communicating facsimile image information by use of electronic mail on the Internet has been developed.
The document RFC(Request For Comments) 2301˜2306 published by the organization responsible for collecting technologies relating to the Internet referred to as IETF(Internet Engineering Task Force), prescribes the technical contents of a communication protocol, etc. employed in such a network facsimile device.
In the Internet, a delivery system has been developed for delivering electronic mail to a sending terminal for confirming the delivery of electronic mail to a destination terminal. This type of e-mail is hereinafter referred to as “a delivery confirming mail”. This type of delivery confirming mail system is capable of confirming whether electronic mail has been delivered to the address of the communication partner to which it has been addressed. This is an expanded function of the electronic mail system.
In such a delivery confirming mail system, the electronic delivery confirming mail is created both when the electronic mail has been delivered to the mail address to which it was sent and when the electronic mail has not been successfully delivered to the mail address to which it has been sent. In each case, electronic delivery confirming mail is created and delivered to the communication partner which sent the electronic mail.
In the above-mentioned network facsimile device, however, there presently exists no method of surely knowing whether electronic mail which is used for carrying the image information has been delivered to the address of the communication partner to which it is to be delivered. Accordingly, other ways of confirming the delivery of the image information must be considered.
However, confirming the delivery of image information by a network facsimile device which uses e-mail delivery presents its own unique problems. For example, when the network facsimile device receives electronic mail addressed to itself, the network facsimile device performs local processing on the electronic mail. Consequently, if a delivery confirming mail were used to confirm delivery of the electronic mail sent from the network facsimile device, the network facsimile device would record and output the contents of the delivery confirming mail. However if, all of the contents of the delivery confirming mails are recorded and outputted, there arises the problem of wasteful consumption of recording paper. In addition, a user would need to be present at the network facsimile device to read the delivery confirming mail to determine whether the delivery was successful. These and other problems need to be addressed and solved.