SMTP(Simple Mail Transfer Protocol) 분석을 통해 알 수 없는 발신자를 차단하는 방법

Abstract

Recently, the damage caused by impersonation or forgery∙alteration of e-mail has been increasing. While the existing spam mail processing system scanned and examined mails such as large mails, advertising mails and junk mails as major targets, it was not able to identify or distinguish impersonations or forged mail. In this study, a new email processing system based on error codes was devised by using the mailing system's unique algorithm. In the proposed system, the error codes related to the loss of e-mail provided by the e-mail system environment are used to determine and process whether the e-mail is normal. An impersonation, forgery∙alteration mail management system is located between the network and the recipient's mail server. When an email is received through the mail account of the mail server, it generates verification request information including the received mail content and sends a verification email to the sender's email address. Thereafter, if the sender mail server provides the verification request information normally, email is delivered to recipient. If the sender's e-mail address is not valid, the error code is returned to the impersonation, forgery∙alteration e-mail management system, and the e-mail is blocked. The proposed system was introduced to an actual institution and performance verification was carried out. As a result of the verification, the proposed system has significantly improved the rate of abnormal mail processing. We hope that the results of this study can serve as a useful guide for the development of email processing systems.