E-mail relay apparatus and e-mail relay method

Abstract

An e-mail relay apparatus notifies a user of which e-mail could not be transmitted if a transmission error has occurred, without consuming a memory capacity. When an e-mail transmission instruction is received and after header information of the received e-mail is stored, a digital signature is added to the e-mail, and the e-mail text is encrypted (S101-S104). Then, after the digital signature is added, the encrypted e-mail is stored, and after the original e-mail is deleted, the transmission of the e-mail is started (S105-S107). If an error has occurred during the e-mail transmission and the transmission has failed, an error-notifying mail addressed to a transmission source is generated. After a header file of the e-mail is attached to the error-notifying mail, the error-notifying mail to which the header file is attached is stored in a mail box for the user of the transmission source (S108-S110).

Description

[0001] This application claims priority to Japanese Patent Application No. 2007-271224 filed on October 18, 2007 under 35 U.S.C.119, the entire contents of which are incorporated in this application. technical field [0002] The present invention relates to a mail relay device, in particular to a mail relay device for encrypting emails and giving digital signatures. Background technique [0003] In e-mail using a computer system, when the sender sends an e-mail, it is stored in the mail server at the address of the management destination, the e-mail is retrieved from the communication terminal on the receiving side, the content is confirmed, and discarded if it is not needed. deal with. [0004] Such e-mail has become an indispensable tool for business communication in business and other occasions because of its convenience, speed, and the like. However, e-mail has risks of eavesdropping, rewriting, falsification, impersonation, etc., so the encryption of e-mail and the giv...

AI Technical Summary

Problems solved by technology

[0009] As mentioned above, when some kind of abnormality occurs in the sending of e-mail, it is necessary to notify that a sending error has occurred, but the user cannot judge which e-mail cannot be sent just by notifying the error.

On the other hand, if the original email is added to the error notification email, although the user can determine which email cannot be sent, in this case, it is necessary to save the original email until the sending of the error notification email is completed.

[0010] However, in the case of storing the original mail in a mail relay device that performs encryption of e-mails and granting of digital signatures, for example, a gateway server, there is a problem that the memory capacity of the gateway server or the communication volume is suppressed.

That is, the memory capacity of the gateway server is usually not too large, but the original e-mail may be very large in size due to attached files, etc., so the memory capacity of the gateway server or communication traffic is suppressed.

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