Abstract: The present invention generally relates to a system for blocking spam mail and a method of the same, and the system in accordance with the present invention, comprising: a Mail transceiver receiving the e-mail, temporarily storing the e-mail in a temporary storage for a set time after authentication mail is transmitted, and deleting the e-mail it a sender's response is not received within the set time, then transmitting the temporarily stored e-mail to mail accounts of recipients of a mail server if the sender's response is received within the set time; an authenticator list classifying and storing, according to each recipient, an e-mail address of the sender authenticated through the authentication mail and an e-mail address of a random sender registered by the recipients of the e-mail to receive the e-mail without authentication; and an authentication processor retrieving whether the e-mail address of the sender is included in the authenticator list, sending the authentication mail to the e-mail address of