JP2003234784A - Method for blocking unsolicited e-mail, and reception server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unsolicited e-mail blocking method for preventing the reception of an unsolicited e-mail such as a spam mail and to provide a reception server. <P>SOLUTION: The reception server 14 which receives e-mails from a transmission server 12 determines whether or not there are a large amount of unknown the destinations of the simultaneously transmitted e-mails (step 106), and returns the e-mails to the transmitter of the transmission server 12 (step 109). The reception server 14 determines whether From-data are a reception permitted address (domain) or not (step 107), and returns the e-mail to the transmitter of the transmission server 12 when the data are not the reception permitted address (domain) (step 109). When 'X-FN' is added to the mail header of the E-mail, the reception server 14 returns the e-mails received from the transmission server 12 to the transmitter of the transmission server 12 (step 109). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for blocking unsolicited electronic mail and a receiving server, and more particularly to a method for blocking unsolicited electronic mail such as spam mail and a receiving server.

[0002]

2. Description of the Related Art Conventionally, in an electronic mail system, unsolicited electronic mail such as spam mail is unilaterally sent irrespective of the intention of the electronic mail user, which only impairs the convenience of the user. However, there are problems such as communication hindrance due to increased traffic in public communication networks such as the Internet network and mobile phone network, and e-mail content that violates public order and morals. Here, spam mails are mostly commercial advertisement mails such as site introductions, and recently are mass mails sent indiscriminately to e-mail addresses of mobile phones. Therefore, various proposals have been conventionally made to block the reception of unsolicited electronic mail such as spam mail (for example, Japanese Patent Laid-Open No. 2000-1088).
No. 0, JP 2000-92114 A, JP 2000-1
No. 63341, etc.). Further, in the conventional i-mode mail, spam mail is blocked according to the flowchart shown in FIG.

A conventional method for blocking unsolicited e-mail will be described with reference to FIG. 3. An e-mail (e-mail) is created in the sender terminal 21 (step 201) and the e-mail is sent to the sending server 22. (Step 202). The transmission server 22 communicates with the reception server 23 (step 203) and transmits the electronic mail received from the sender terminal 21 to the reception server 23 (step 204). The receiving server 23 communicates with the transmitting server 22 (step 205), determines whether or not a large number of unknown recipients of the electronic mail received from the transmitting server 22 include (step 206), and includes a large amount. If
Since it is a junk e-mail, the e-mail is sent back from the receiving server 23 to the sender (step 206). If the e-mail is not included in a large amount, it is determined whether the from data is an address (domain) which the reception is permitted (step). 20
7).

Here, in spam mail, a non-existent mail address is often disguised as a from address. The from address is a sender's mail address, and is present as "from data" in a mail header which is control data attached to an electronic mail.
Therefore, in the above step 207, it is judged whether the reception of the from data is permitted. If the reception is not permitted, it is determined that the received data is spam mail and the e-mail is returned from the receiving server 23 to the sender (step 206). ).

On the other hand, when it is judged in the above step 207 that the reception of the from data is permitted, it is judged that the electronic mail is of the century, and the electronic mail received from the receiving server 23 is transmitted to the receiver terminal 24. (Step 20
9). The recipient terminal 24 receives the e-mail addressed to itself from the receiving server 23 (step 210). In this way, conventionally, the method of designating the address domain which the user side refuses or permits the mail reception, and the receiving server 2
There are two main methods of blocking e-mails containing a large number of unknown recipients on the 3 side to block unsolicited e-mails (NT Corporation)
(For T-DOCOMO service "i-mode").

[0006]

However, in the above-mentioned conventional method for blocking unwanted e-mail, the receiving server 23 is used.
Although it is judged whether the from address is invalid (cannot reply), as a result, when it is judged that "reply to sender" is possible, "X-F" is included in the mail header of the e-mail. Header information is added, and when it is determined that "the reply cannot be sent to the sender", the header information "X-FN" is only added in the e-mail header, and it may be illegal (X- FN) or not (XF), sending an email to the recipient.
Therefore, conventionally, spam emails disguised as From Data could not be completely blocked and were sent to the destination.

Further, in the conventional method for blocking unsolicited e-mail described in each of the above-mentioned publications, a very large number of e-mails from the same sender and / or e-mails of unknown sender are used as the e-mail reception condition information. If detected based on
A method for automatically excluding the e-mail (Japanese Patent Laid-Open No. 2000-2000)
No. 163341) or a word or phrase representing the content of an electronic mail that is not transferred to an electronic mail server is stored in advance, and it is determined whether or not there is a match with the stored word or phrase in the text of the received electronic mail. If there is a matching phrase, a method (Japanese Patent Laid-Open No. 2000-10880) in which the electronic mail is not transferred to the electronic mail server is disclosed. However, all of these methods use the above-mentioned form. You cannot completely block spam emails that are disguising your data.

The present invention has been made in view of the above points,
An object of the present invention is to provide a method for blocking unsolicited e-mail and a receiving server which can prevent unsolicited e-mail such as spam mail from being received.

[0009]

In order to achieve the above object, the method for blocking unwanted e-mail according to the first aspect of the present invention, prior to transmitting the received e-mail to the recipient's recipient terminal,
When it is determined in the mail server that the received e-mail can be sent back to the sender, the first information added to the e-mail header of the e-mail and the received e-mail will be displayed in the mail server. The first step of determining which of the second information added in the mail header of the electronic mail is added, When it is determined in step 1 that the second information is added, the second step of returning the received e-mail to the sender instead of sending the received e-mail to the sender, and the first step Thus, when it is determined that the first information is added, the third step of transmitting the received electronic mail to the recipient terminal as the destination is included.

According to the present invention, when it is determined that the received e-mail cannot be returned to the sender in the mail server, the second information added in the mail header of the e-mail is detected. The e-mail is judged to be an unsolicited e-mail such as spam mail and is not sent to the recipient terminal of the destination but returned to the sender.

In the method for blocking unwanted e-mail according to the second aspect of the invention, the received e-mail can be "replied to the sender" in the mail server before the received e-mail is sent to the recipient terminal as the destination. If it is determined that the first information added to the email header of the email and the received email is "cannot reply to the sender" in the email server, the email Of the second information added in the mail header of the first email, the first condition in which the second information is added, and a predetermined number of unknown destinations to which the received email is sent at the same time. The first step of judging whether any one of the condition 2 and the third condition in which the sender address of the received electronic mail is an address (drain) which is not permitted to be received is satisfied. If it is determined by the first step that any one of the first to third conditions is satisfied, the received e-mail is not sent to the recipient terminal of the destination, but sent to the sender. The second step of returning
When it is determined by the first step that all of the first to third conditions are not satisfied, the third step of transmitting the received electronic mail to the recipient terminal as the destination is included.

According to the present invention, when a second condition is met in which a predetermined number or more of unknown destinations are simultaneously transmitted to the received electronic mails, a large amount of electronic mails with unknown destinations, that is, unsolicited electronic mails are considered. Also, when the sender's address of the received e-mail is the address (drain) that is not permitted to receive the third condition,
If the received e-mail is judged to be unsolicited e-mail, it is not sent to the recipient's recipient's terminal as before, and if the e-mail is judged to be "unable to reply to the sender", the e-mail When the second information added in the header is detected, the e-mail is determined to be unsolicited e-mail such as spam mail and is not sent to the recipient terminal as the destination.

Here, the above-mentioned first information is the header information "X-" obtained by making a determination in the i-mode mail server.
The second information is header information "X-FN" obtained by making a determination in the i-mode mail server.

Further, in order to achieve the above object, the receiving server of the fourth invention is a receiving server for transmitting an electronic mail received from a transmitting server via a network to a destination recipient terminal, and receiving the electronic mail. When the email server determines that it can reply to the sender, the first information added to the email header of the email and the received email will be returned to the sender in the email server. When it is determined that the second information is added, the determination means that determines which of the second information added in the mail header of the electronic mail is added, When it is determined that the information has been added, a return means for returning the received email to the transmission server via the network without transmitting the received email to the recipient's terminal The stage, when the first information is determined to be added is obtained by a configuration having a transmitting means for transmitting the received e-mail to the destination of the receiver terminal.

According to the present invention, when the received e-mail is judged as "cannot reply to the sender" in the mail server, the second information added in the mail header of the e-mail is detected. The e-mail is judged to be an unsolicited e-mail such as spam mail and is not sent to the recipient terminal of the destination but returned to the sender.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of an electronic mail system having a receiving server according to the present invention,
FIG. 2 shows a flowchart of an embodiment of a method for blocking unsolicited electronic mail according to the present invention. The electronic mail system shown in FIG. 1 includes a sender terminal 11, a sending server 12, the Internet 13, a receiving server 14, and a recipient terminal 15.
It consists of The receiving server 14 is the transmitting server 1
2 and the Internet 13 are connected.

The general operation of the electronic mail system of FIG. 1 will be described. The sender terminal 11 creates an e-mail based on the operation of the sender, and then passes the created e-mail to the transmission server 12. The transmission server 12 communicates the received e-mail with the reception server 14 which is the transmission destination via the Internet 13, and passes the e-mail to the reception server 14. The receiving server 14 determines whether or not the electronic mail received from the transmitting server 12 is an unsolicited electronic mail, returns the unsolicited electronic mail to the sender, and passes only the unsolicited electronic mail to the recipient. .

Here, in the present embodiment, the receiving server 1
4 determines whether the electronic mail received from the transmission server 12 is an unsolicited electronic mail based on whether the from data is invalid. There are several possible criteria for determining whether the from data is invalid, but in the present embodiment, the criteria for "whether or not to reply to the sender" that is used in the i-mode mail server is used. .

When it is determined in the receiving server 14, which is an i-mode mail server, that "a reply can be made to the sender" for a certain electronic mail, header information "X-F" is added to the mail header of the electronic mail. To be done. vice versa,
When it is determined that an e-mail cannot be replied to due to reasons such as using double-byte characters in the e-mail address of the sender, "X-FN" is included in the mail header of the e-mail. Header information is added. Currently, even if the header information "X-FN" exists in the mail header, the electronic mail is sent to the destination (destination).

Therefore, in the receiving server 14 of the present embodiment, when the header information of "X-FN" exists, the electronic mail is judged to be unsolicited electronic mail and is not sent to the destination but blocked. Blocking unwanted e-mail such as spam mail by sending it back to the sender.
Since the method of determining the from data by the receiving server 14 and the method of adding the X-F / X-FN information are known, the description thereof will be omitted here.

Next, referring to the flowchart of FIG.
The overall operation of this embodiment will be described. First, the sender operates the sender terminal 11 to create an electronic mail (step 101), and sends the electronic mail created by the sender terminal 11 to the transmission server 12 (step 102).
The sending server 11 that has received the email from the sender terminal
Searches the receiving server 14 from the destination of the electronic mail, communicates with the receiving server 14 via the Internet 13 (step 103), and transmits the electronic mail to the receiving server 14 via the internet 13 (step 1).
04).

The receiving server 14, which communicates with the transmitting server 12 via the Internet 13 (step 105) and receives the electronic mail from the transmitting server 12, refers to the mail header of the electronic mail and determines the following from data. . First, it is determined whether or not a large number of unknown addresses are included in the destinations transmitted at the same time (step 106), and if a large amount is included, it is determined that the email is unsolicited email such as spam email and the email received from the transmission server 12 is determined. Is sent back to the sender of the sending server 12 (step 109).

In the case of an electronic mail that does not include a large number of unknown destinations sent at the same time, the receiving server 14 determines the address (domain) from which the from data is permitted to receive.
It is judged whether or not (step 107), and if the address (domain) is not permitted to be received, it is judged to be unsolicited e-mail such as spam mail, and the e-mail received from the sending server 12 is sent to the sending server 12. It is sent back to the sender (step 109).

Further, when the from-data is an address (domain) which the recipient permits to receive, the receiving server 14 further determines whether "X-FN" is added to the mail header of the electronic mail. (Step 108). If the e-mail is invalid, the e-mail is "cannot reply to the sender" that is disguised as the from data, and in this case, "X-
Since "FN" is added, when "X-FN" is added, the receiving server 14 determines that the email is unsolicited email such as spam email, and sends the email received from the sending server 12 to the sending server. It is sent back to the sender via 12 (step 109).

On the other hand, "X-
If "FN" is not added, the received mail 14 is
It is determined that the e-mail is correct, and the e-mail received from the transmission server 12 is sent to the recipient terminal 15 of the destination.
(Step 110). The recipient terminal 15 receives the e-mail from the receiving server 14 (step 11
1) Pass it to the recipient.

In this way, according to the present embodiment,
"X-FN" is added to the mail header in addition to sending e-mails containing a large number of unknown recipients and e-mails that are not addresses (domains) from which the data is allowed to be received to the recipient. The email that is being sent
Since the sender disguising the From-Data is malicious email, the email is not sent to the recipient but is sent back to the sender, so that the recipient can avoid receiving unsolicited email such as spam email.

[0027]

As described above, according to the present invention,
If the second information added in the mail header of the e-mail is detected when it is determined that the received e-mail is "cannot reply to the sender" in the mail server,
Judging that the e-mail is unsolicited e-mail such as spam e-mail, it will not be sent to the recipient's recipient's terminal, but will be returned to the sender, so unsolicited e-mail such as spam cannot be received at the recipient's terminal. Can be prevented.

Further, according to the present invention, when the second information added in the mail header of the electronic mail which is judged to be "cannot reply to the sender" is detected, the electronic mail is addressed to the recipient. When the spam mail blocking method of the present invention that does not send to a terminal and the second condition including a predetermined number or more of unknown recipients of received emails at the same time are satisfied, a large amount of emails with unknown recipients, that is, Even when it is determined that the email is unsolicited email and the source address of the received email is the address (drain) that is not permitted to receive the third condition, the received email is unsolicited email. We decided to combine it with the conventional method of blocking unsolicited e-mail that does not send it to the recipient's recipient's terminal, so that it can almost completely receive unsolicited e-mail. It is possible to click.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of an electronic mail system having a receiving server according to the present invention.

FIG. 2 is a flowchart of an embodiment of a method for blocking unwanted e-mail according to the present invention.

FIG. 3 is a flowchart of an example of a conventional spam email blocking method.

[Explanation of symbols] 11 Sender terminal 12 Sending server 13 Internet 14 Receiving server 15 Recipient terminal

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Claims (6)

[Claims] 1. A mail of an electronic mail, when the received electronic mail is judged to be “replyable to the sender” in the mail server before the received electronic mail is transmitted to the recipient terminal of the recipient. The first information added in the header,
When the received e-mail is determined to be "cannot reply to the sender" in the mail server, which of the second information added to the mail header of the e-mail is added And the first step of determining whether the second information is added by the first step, the received e-mail is not transmitted to the recipient terminal of the destination. A second step of returning to the sender, and when it is determined by the first step that the first information is added, the received e-mail is transmitted to the recipient terminal as the destination. A method for blocking unsolicited e-mail, the method including a third step. 2. The e-mail of the received e-mail when it is determined in the mail server that “the reply can be made to the sender” before the received e-mail is transmitted to the recipient terminal of the destination. The first information added in the header,
When the received e-mail is determined in the mail server as "cannot reply to the sender", the second information is added to the second information added to the mail header of the e-mail. The first condition that is set, the second condition that the destinations of the received electronic mail to be simultaneously transmitted include an unknown number or more, and the sender address of the received electronic mail is not permitted to be received. A first step of determining whether any one of the third conditions of address (drain) is satisfied, and any one of the first to third conditions according to the first step. When it is determined that one condition is satisfied, the second step of returning the received e-mail to the sender without sending the received e-mail to the recipient terminal, and the first step, Note that when it is determined that all of the first to third conditions are not satisfied, a third step of transmitting the received electronic mail to the recipient terminal as the destination is included. Block method. 3. The first information is header information “X-F” obtained by making a determination in the i-mode mail server, and the second information is a determination in the i-mode mail server. The unsolicited email blocking method according to claim 2, wherein the obtained header information is "X-FN". 4. A receiving server, which transmits an electronic mail received from a transmitting server via a network to a recipient terminal as a destination, determines that the received electronic mail is “replyable to a sender” in the mail server. Sometimes, when the first information added in the mail header of the e-mail and the received e-mail is determined to be “unable to reply to the sender” in the mail server, the e-mail of the e-mail Of the second information added in the header, a determination unit that determines which information is added, and when the determination unit determines that the second information is added, The return means for returning the received email to the transmission server via the network without transmitting the received email to the recipient terminal, And a sending unit that sends the received e-mail to the recipient terminal as the destination when it is determined that the information is added. 5. A receiving server for transmitting an electronic mail received from a transmission server via a network to a destination recipient terminal, the received electronic mail before transmitting the received email to the destination recipient terminal. Is determined to be "replyable to the sender" in the mail server, the first information added to the mail header of the email and the received email are "source" in the mail server. Cannot be replied to ”, the first condition in which the second information is added among the second information added in the mail header of the email and the received email. And a second condition that includes a predetermined number or more of unknown destinations to be simultaneously transmitted, and the source address of the received electronic mail is an address (drain) that is not permitted to be received. And a determination unit that determines whether or not one of the conditions is satisfied, and the determination unit determines that one of the first to third conditions is satisfied. At times, the return means for returning the received e-mail to the recipient server as a destination without returning to the recipient terminal, and the determining means, all the first to third conditions A receiving server comprising: a transmitting unit that transmits the received e-mail to the recipient terminal as a destination when it is determined that the received e-mail is not satisfied. 6. The first information is header information “X-F” obtained by making a determination in the i-mode mail server, and the second information is a determination in the i-mode mail server. The receiving server according to claim 5, wherein the header information is "X-FN" obtained by performing the processing.