JP6993898B2 - Email system - Google Patents

Description

The present invention relates to an e-mail system that prevents the reception of unsolicited e-mail, particularly an e-mail system that prevents the reception of a large amount of spam mail.

In recent years, with the spread of e-mail, the importance of measures against unsolicited e-mail has increased. For example, in Patent Document 1, a sending-side mail server and a receiving-side mail server store a set of source and destination mail addresses in association with a sending password, and use this sending password. An e-mail system that determines the handling of unsolicited e-mail is disclosed. In this e-mail system, the sending mail server adds a unique header with the sending password to the e-mail and forwards it to the receiving mail server, while the receiving mail server adds a unique header to the e-mail. It is judged whether or not the sending password written in the mail matches the stored sending password, and if it matches, it is judged that it is not a junk mail and an e-mail is sent to the receiving user's mail address. do. Here, if the sending passwords do not match, the receiving mail server notifies the sending mail server of a temporary error and waits for resending, while notifying the receiving user terminal of the sending mail address and receiving. Inquire whether to allow. As a result, if permission is obtained by the receiving user, the receiving mail server delivers the resent email, and if permission is not obtained, an error is returned to the sending mail server. As a result, the e-mail that is not authenticated by the sending password and the permission of the receiving user is not obtained is not sent to the receiving user side, and it is prevented from receiving the junk mail.

Japanese Unexamined Patent Publication No. 2011-180898

As described above, in the case of the above-mentioned conventional e-mail system, when the authentication by the transmission password cannot be performed, the receiving user is inquired about the acceptance / rejection of reception. Therefore, when the number of unsolicited e-mails is large, an inquiry is made each time, and there is a problem that a complicated response is required.

The present invention has been made in view of such circumstances, and a main object thereof is to provide an e-mail system capable of preventing unsolicited e-mail without imposing an excessive burden on the recipient side. ..

In order to solve the above-mentioned problems, the e-mail system according to one aspect of the present invention has a storage unit that stores a set of a sender address and a receiver address of the e-mail, and when the e-mail is received from an external device. A determination means for determining whether or not a set of a sender address and a receiver address of the e-mail is stored in the storage unit, and when the determination means determines that the set is stored, the electron. A first transmitting means for transmitting an email to a receiving side address, and a requesting means for requesting a specific input operation from the sender side of an e-mail when the determination means determines that the set is not stored. When the input operation is performed on the sender side as a result of the request by the request means, the second transmission means for transmitting the e-mail to the receiving side address is provided.

In the embodiment, the storage unit may be configured to store a set of a sender address and a receiver address of the e-mail when the input operation is performed on the sender side.

Further, in the above aspect, when an input operation different from the input operation is performed on the sender side as a result of the request by the request means, the second transmission means is an address including the sender address of the e-mail. The information may be configured to be sent to the recipient address of the e-mail.

Further, in the above aspect, when an input operation different from the input operation is performed on the sender side as a result of the request by the request means, an erroneous input address recording means for recording the sender address of the e-mail is further provided. When a plurality of sender addresses are recorded by the erroneously input address recording means, the second transmission means shall transmit the address information including the plurality of sender addresses to the receiver address of the e-mail. It may be configured in.

Further, in the above aspect, when the approval information indicating that the sender address included in the address information is approved is received from the destination side of the e-mail, the e-mail related to the sender address is sent to the receiver address. A third transmission means for transmitting to may be further provided.

Further, in the above aspect, when non-approved information indicating that the sender address included in the address information has not been approved is received from the destination side of the e-mail, the sender address is recorded as a reception refusal address. Further, the reception refusal address recording means may be provided.

According to the e-mail system according to the present invention, it is possible to effectively prevent the reception of unsolicited e-mail without imposing an excessive burden on the recipient side.

The block diagram which shows the structure of the e-mail receiving server and the communication destination thereof which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the e-mail receiving server which concerns on Embodiment 1 of this invention. The figure which shows an example of the layout of the authenticated database provided in the e-mail receiving server which concerns on Embodiment 1 of this invention. The flowchart which shows the procedure of the e-mail reception processing executed by the e-mail reception server which concerns on Embodiment 1 of this invention. The flowchart which shows the procedure of the erroneous input address notification processing executed by the e-mail receiving server which concerns on Embodiment 1 of this invention. The flowchart which shows the procedure of the receiver side approval process which is executed by the e-mail receiving server and the user terminal which concerns on Embodiment 1 of this invention. The flowchart which shows the procedure of the reception refusal setting process executed by the e-mail receiving server and the user terminal which concerns on Embodiment 1 of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. It should be noted that each embodiment shown below exemplifies a method and an apparatus for embodying the technical idea of the present invention, and the technical idea of the present invention is not limited to the following. do not have. The technical idea of the present invention may be modified in various ways within the technical scope described in the claims.

(Embodiment 1)
[E-mail system configuration]
FIG. 1 is a block diagram showing a configuration of an e-mail system and a communication destination thereof according to an embodiment of the present invention. The e-mail system of the present embodiment is composed of the e-mail receiving server (hereinafter, simply referred to as “reception server”) 1 in FIG. The receiving server 1 is a device for receiving e-mail (including SMS (Short Message Service); the same shall apply hereinafter), and is an e-mail transmitting server (hereinafter, simply referred to as “sending server”) 2 and. It is communicably connected to a plurality of user terminals 3, 3, ... Provided on each user side for sending and receiving e-mail via the Internet 101. The user terminals 3, 3, ... Are composed of devices having a communication function, such as a personal computer, a mobile phone, and a tablet terminal.

[E-mail reception server configuration]
Hereinafter, the detailed configuration of the reception server 1 described above will be described.
FIG. 2 is a block diagram showing the configuration of the receiving server 1. As shown in FIG. 2, the computer (reception server) 1 includes a CPU 11, ROM 12, RAM 13, hard disk 14, and communication interface (I / F) 15, and these CPU 11, ROM 12, RAM 13, hard disk 14, and communication. The I / F 15 is connected by the bus 16.

The CPU 11 executes various computer programs loaded in the RAM 13. As a result, the computer 1 functions as the receiving server 1 of the present embodiment.

The ROM 12 is composed of a mask ROM, a PROM (Programmable ROM), an EPROM (Erasable PROM), an EEPROM (Electrically Erasable PROM), or the like, and is a computer program executed by the CPU 11 and data used for the execution thereof. Is remembered.

The RAM 13 is composed of an SRAM, a DRAM, or the like. The RAM 13 is used for reading various computer programs stored in the hard disk 14. It is also used as a work area for the CPU 11 when the CPU 11 executes various computer programs.

Various computer programs for being executed by the CPU 11 and data used for executing the computer programs are pre-installed on the hard disk 14. Further, the hard disk 14 has an authenticated database (DB) 14A in which an authenticated pair of a sender address and a receiver address is stored, and a user who has made an erroneous input in a character string input described later. An erroneous input address database (DB) 14B in which the relevant e-mail address is stored, and a reception refusal address database (DB) 14C in which the e-mail address set as the reception rejection address at the request of the recipient of the e-mail is stored. Is provided. Details of each of these databases will be described later.

Further, a multitasking operating system such as Windows (registered trademark) manufactured and sold by Microsoft Corporation in the United States is installed on the hard disk 14. In the following description, it is assumed that various computer programs run on the operating system.

The communication I / F 15 is an interface device for the receiving server 1 to communicate with an external device via the Internet 101. The receiving server 1 transmits and receives various data to and from the transmitting server 2 and the user terminals 3, 3, ... Via the communication I / F15.

Hereinafter, the details of each database provided in the hard disk 14 will be described.
(A) Certified DB14A
FIG. 3 is a diagram showing an example of the layout of the authenticated DB 14A provided in the receiving server 1. As shown in FIG. 3, the authenticated DB 14A has a sender address field 111 in which the sender address is stored and a receiver address field 112 in which the receiver address is stored. In this authenticated DB 14A, a set of a sender address confirmed by the recipient of the e-mail to be not the sender of the junk e-mail and the e-mail address (receiver address) of the recipient is stored. There is. In addition, when it is confirmed by the process described later that the e-mail is not the sender of the junk e-mail, the pair of the sender address and the receiver address is stored in the authenticated DB 14A.

(B) Incorrect input address DB14B
As will be described later, when the receiving server 1 receives an e-mail whose sender address is an unauthenticated address, the receiving server 1 requests the input of a specific character string to the sender address. As a result of the request, if a character string different from the character string is input, that is, if an erroneous input is made, the receiving server 1 erroneously inputs a set of the sender address and the email receiver address. Register in DB14B. Therefore, in the erroneous input address DB 14B, a set of a sender address related to the user who made the erroneous input and a receiver address of the e-mail transmitted from the sender address is accumulated. The layout of the erroneously input address DB 14B is the same as that of the authenticated DB 14A.

(C) Rejection address DB14C
As will be described later, the receiving server 1 receives a request from the user and sets a specific e-mail address (sender address) as the reception refusal address. In the reception refusal address DB 14C, a set of a transmission side address thus set as a reception refusal address and an e-mail address (reception side address) related to the user is accumulated. The layout of the reception refusal address DB14C is the same as that of the authenticated DB14A.

[Email system operation]
Next, the operation of the e-mail system of the present embodiment configured as described above will be described with reference to a flowchart and the like. In the following, (1) e-mail reception processing for properly handling the e-mail forwarded from the transmission server 2, (2) erroneous input address notification processing for notifying the contents registered in the erroneous input address DB 14B, The details are divided into (3) sender address approval process for approving the sender address by the recipient of the e-mail, and (4) reception rejection setting process for setting the reception rejection address. explain.

(1) E-mail reception process A user who sends an e-mail (hereinafter referred to as "sender") instructs the user terminal 3 to send an e-mail after designating a receiving side address. The user terminal 3 that has received this instruction transmits an e-mail including a sender address and a receiver address, which are e-mail addresses related to the sender, to the transmission server 2. When the transmission server 2 receives this e-mail, it forwards it to the receiving side address. As a result, the receiving server 1 set as the receiving server of the receiving side address receives this e-mail. Hereinafter, the details of the e-mail reception process executed at the time of reception will be described.

FIG. 4 is a flowchart showing a procedure of e-mail reception processing executed by the reception server 1 of the present embodiment. As shown in FIG. 4, when the receiving server 1 receives the e-mail forwarded from the transmitting server 2 as described above (S101), the pair of the transmitting side address and the receiving side address of the e-mail is received. It is determined whether or not the rejected address is registered in the DB 14C, that is, whether or not the sender address is set as the reception rejected address (S102). Here, when it is determined that the sending side address is set as the receiving side address (YES in S102), the receiving server 1 ends the process without sending the e-mail to the receiving side address. As a result, the e-mail from the sender address set as the reception refusal address will be treated as junk e-mail.

On the other hand, when it is determined in step S102 that the sender address is not set as the reception refusal address (NO in S102), the receiving server 1 refers to the authenticated DB 14A (S103) and uses the e-mail sender address. It is determined whether or not the pair with the receiving side address is registered in the authenticated DB 14A (S104). Here, when it is determined that this set is registered in the authenticated DB 14A (YES in S104), the receiving server 1 determines that this e-mail is not junk e-mail, and sends the e-mail to the receiving side address. Send (S105). As a result, the user related to the receiving side address (hereinafter referred to as "recipient") can receive the e-mail using the user terminal 3.

On the other hand, when it is determined in step S104 that the pair of the transmitting side address and the receiving side address is not registered in the authenticated DB 14A (NO in S104), the receiving server 1 sets the variable n to 1 (S106). .. This n is a counter variable for comparison with a predetermined set value. This set value is a value that determines the allowable number of times of erroneous input at the time of character input described later, and may be 1 or 2 or more. However, considering that it is necessary to tolerate a certain degree of erroneous input due to force majeure such as a typo, it is preferably 2 or more.

Next, the receiving server 1 sends an e-mail containing a URL for displaying a character string input screen showing a specific character string and an input field for inputting the character string to the sender address (). S107). When the user terminal 3 on the sender side accesses this URL, the character string input screen is displayed on the display unit. Here, if the sender is a human being, the specific character string displayed on the character string input screen can be referred to and input. On the other hand, when the sender is a robot or the like that sends a spam mail, the specific character string cannot be recognized, so that the character string cannot be input in the input field. Therefore, it is possible to determine whether or not the sender is a robot or the like by determining whether or not the correct character string has been input. In addition, in order to make this determination more reliably, it is preferable that the specific character string is composed of modified characters and the like.

When a character string is input to the character string input screen, the receiving server 1 acquires the character string and determines whether or not it is a correct character string (S108). Here, if it is determined that the input character string is the correct character string (YES in S108), the receiving server 1 determines that this e-mail is not junk e-mail, and the sender address and the receiver of the e-mail. The pair with the address is registered in the authenticated DB 14A (S109). After that, the receiving server 1 transmits the e-mail to the receiving side address (S110). As a result, the recipient can normally receive the e-mail even when the e-mail is transmitted from the sender address to the receiver address for the first time. Information indicating that the registration to the authenticated DB 14A has been made may also be transmitted to the receiving side address. In that case, an e-mail containing the information may be transmitted in step S110, or the information may be transmitted separately from the e-mail.

On the other hand, when it is determined in step S108 that the character string input is not the correct character string (NO in S108), the receiving server 1 determines whether or not n has reached the set value (S111). Here, if it is determined that the value has not been reached (NO in S111), the receiving server 1 increments the value of n by 1 (S112), and returns to step S107. This iterative process is continued until it is determined in step S111 that n has reached the set value.

When it is determined in step S111 that n has reached the set value (YES in S111), the receiving server 1 registers the pair of the sending side address and the receiving side address of the e-mail in the erroneous input address DB 14B (S113). , End the process.

In the case of the above e-mail reception process, for the e-mail related to the set of the sender address and the receiver address that is not registered in the authenticated DB 14A, the recipient when the correct character string is input on the sender side. It will be sent to the side. Therefore, it is possible to take measures against unsolicited e-mail without forcing the recipient to take excessive measures.

Further, in the case of the above e-mail reception process, if the correct character string is input, the pair of the e-mail sender address and the receiver address is registered in the authenticated DB 14A, so that the sender is subsequently registered. When an e-mail is sent from the address to the receiving side address, it is determined that the e-mail has been authenticated in step S104 above without being requested to input the character string again to the sender side, and the process is performed in step S105. The email will be sent to the recipient's address. This prevents the sender from being overloaded.

(2) Incorrect input address notification process When an incorrect character string is input a predetermined number of times, the sender address is registered in the erroneous input address DB 14B as an erroneous input address by the above e-mail reception process. The sender address registered in the erroneous input address DB 14B in this way is notified to the receiver address by the following erroneous input address notification process.

FIG. 5 is a flowchart showing a procedure of erroneous input address notification processing executed by the receiving server 1 of the present embodiment. It should be noted that this erroneous input address notification process is executed for each e-mail address (receiver address) on the receiver side.

As shown in FIG. 5, the receiving server 1 has elapsed a preset period from the time of the previous notification of the erroneously input address for the e-mail address to be processed (hereinafter referred to as “processing target address”). It is determined whether or not it is (S201). This period can be any value (eg, one week, etc.). If it is determined that the period has not elapsed (NO in S201), the receiving server 1 returns to step S201. On the other hand, when it is determined that the period has elapsed (YES in S201), the receiving server 1 extracts the sender address associated with the processing target address in the erroneous input address DB 14B as the erroneous input address (YES in S201). S202). Here, when a plurality of erroneous input addresses are stored in the erroneous input address DB 14B for the processing target address, all the erroneous input addresses are extracted.

Next, the receiving server 1 generates an e-mail including the extracted erroneous input address, and transmits the e-mail to the processing target address (reception side address) (S203). As a result, the recipient can confirm the erroneously entered address, so that it is possible to grasp from what address the e-mail suspected to be junk e-mail was sent. Of the sender addresses notified as erroneous input addresses, the sender address that the recipient can trust is approved by the sender address approval process described later, while the untrustworthy sender address is set to reject reception described later. It can be set as a reception rejection address by processing. When transmitting a plurality of erroneously input addresses to the receiving side address, it is preferable to sort and transmit the plurality of erroneously input addresses for each domain. This makes it possible to easily perform the sender address approval process or the reception refusal setting process.

In the case of this embodiment, as described above, the erroneous input address is notified every time a certain period of time elapses. It is possible to notify the erroneous input address to the receiving side address each time it is determined to be an erroneous input address, but if the number of receiving side addresses recognized as erroneous input addresses is relatively large, the frequency of receiving notifications is high. Since it is expensive and annoying, it is preferable that the erroneous input addresses are collectively sent at regular intervals as in the present embodiment.

(3) Sender address approval process The receiver knows the erroneous input address by the erroneous input address notification process described above. If the recipient has a credible sender address among the erroneously entered addresses, the receiver causes the following sender address approval process to be executed in order to request receipt of the e-mail related to the sender address.

FIG. 6 is a flowchart showing the procedure of the sender address approval process executed by the receiving server 1 and the user terminal 3 of the present embodiment. The receiver identifies a credible address from the notified erroneous input addresses, and inputs the approval address information including the address to the user terminal 3. The user terminal 3 that has received this transmits the approval address information to the receiving server 1 (S301).

When the receiving server 1 receives the approval address information transmitted from the user terminal 3 (S401), the receiving server 1 authenticates the set of the transmitting side address included in the approval address information and the receiving side address related to the recipient DB 14A. Register in (S402). Next, the receiving server 1 transmits an e-mail relating to the pair of the transmitting side address and the receiving side address registered in the authenticated DB 14A to the receiving side address (S403). As a result, the e-mail of the sender address specified by the receiver can be received by the receiver even if the sender address is an erroneous input address. From this point onward, the e-mail related to this combination of the sending side address and the receiving side address will be sent to the receiving side address without being determined as junk mail by the above e-mail receiving process. ..

(4) Rejection setting process If the recipient has an untrustworthy sender address among the incorrect input addresses, the recipient executes the following reception refusal setting process in order to refuse to receive the e-mail related to the sender address. Let me.

FIG. 7 is a flowchart showing a procedure of reception refusal setting processing executed by the reception server 1 and the user terminal 3 of the present embodiment. The receiver identifies an untrustworthy address from the notified erroneous input addresses, and inputs the reception refusal address information including the address to the user terminal 3. The user terminal 3 that has received this transmits the reception refusal address information to the receiving server 1 (S501).

When the receiving server 1 receives the reception refusal address information transmitted from the user terminal 3 (S601), the receiving server 1 receives a set of the transmitting side address included in the reception refusal address information and the receiving side address related to the receiver. Register in the deny address DB14C (S602). Next, the receiving server 1 sends an e-mail indicating that the reception refusal setting is completed to the receiving side address (S603). After that, the e-mail related to the combination of the sending side address and the receiving side address will be determined to be junk mail by the above-mentioned e-mail receiving process, and will not be sent to the receiving side address.

(Embodiment 2)
The e-mail system of the first embodiment is configured by the receiving server 1. On the other hand, the e-mail system of the present embodiment is configured by the transmission server 2. In that case, the transmission server 2 has a database similar to the authenticated DB 14A, the erroneous input address DB 14B, and the reception refusal address DB 14C in the first embodiment. Then, when the transmission server 2 receives the e-mail addressed to the specific receiving side address from the user terminal 3 on the sender side, the transmission server 2 performs the above-mentioned e-mail receiving process before transmitting the e-mail to the receiving side address. Perform the same process. As a result, as in the case of the first embodiment, it is possible to take measures against unsolicited e-mail without forcing the receiver to take excessive measures.

(Other embodiments)
In the above embodiment, the e-mail system requires the sender to input a specific character string, but other input operations may be requested. Specifically, input operations such as selecting a specific image from a plurality of images and checking a specific check box are assumed. In addition to paying attention to the input content in this way, the input method may also be considered. For example, when the e-mail system requests the sender to input voice, if the input is performed by keyboard input, it is determined that the correct input has not been made, and the input is registered in the erroneous input address DB 14B. You may do it.

Further, in the above embodiment, it is determined for each e-mail address whether or not it has been authenticated, and whether or not it corresponds to junk e-mail is determined based on the determination result. Not limited to. For example, it may be determined whether or not each domain has been authenticated. In that case, it is possible to efficiently deal with the situation where unsolicited e-mail is sent from a plurality of sender addresses of the same domain.

Further, in the above embodiment, it is determined that the e-mail related to the combination of the sender address and the receiver address registered in the authenticated DB 14A is not junk mail, but for example, the authenticated DB 14A is concerned. If a certain period of time has passed since the group was registered, it may be determined that there is a possibility of junk mail, and a process for requesting the input of a subsequent character string may be performed. In this case, when the correct character string is input, it is conceivable to re-register the set in the authenticated DB 14A.

Further, in the above embodiment, if the pair of the sender address and the receiver address is not registered in the authenticated DB 14A, it is determined that the e-mail may be junk e-mail and subsequent processing is performed. However, the present invention is not limited to this. For example, although the pair of the sender address and the receiver address of the forwarded e-mail is not registered in the authenticated DB 14A, another e-mail address in the same domain as the receiver address and the sender address thereof. If the pair with is registered, it may be determined that the e-mail is not junk e-mail and sent to the receiving address. This makes it possible, for example, to determine that an e-mail from a sender's address that has already been approved by a person in a certain organization is not a junk e-mail to another person in the organization.

Further, in the above-described embodiment, the function of the e-mail system (reception server 1 or transmission server 2) is realized by a single computer, but the function of the e-mail system is realized by, for example, a distributed system by a plurality of computers. It may be, and various aspects are assumed.

1 E-mail receiving server 11 CPU
12 ROM
13 RAM
14 Hard disk 14A Authenticated database 14B Incorrect input address database 14C Rejection address database 15 Communication interface 16 Bus 2 E-mail transmission server 3 User terminal 101 Internet

Claims (6)

A storage unit that stores a set of a receiver address of each of a plurality of recipients of e-mail and a sender address confirmed by each of the recipients to be not the sender of junk mail .
When an e-mail is received from an external device, a determination means for determining whether or not a set of a sender address and a receiver address of the e-mail is stored in the storage unit, and a determination means.
When it is determined by the determination means that the set is stored, the first transmission means for transmitting the e-mail to the receiving side address and the first transmission means.
When the determination means determines that the set is not stored, the request means for requesting a specific input operation from the sender side of the e-mail and the request means.
When the input operation is performed on the sender side as a result of the request by the request means, the second transmission means for transmitting the e-mail to the receiver address and the second transmission means.
When it is determined by the determination means that the set is not stored, a set of another e-mail address having the same domain as the receiving side address and the transmitting side address is stored in the storage unit. Occasionally, with a third transmission means for transmitting the e-mail to the receiving address.
E-mail system with. The storage unit is configured to store a set of a sender address and a receiver address of the e-mail when the input operation is performed on the sender side.
The e-mail system according to claim 1. When an input operation different from the input operation is performed on the sender side as a result of the request by the request means, the second transmission means transfers the address information including the sender address of the e-mail to the e-mail. It is configured to send to the receiving address,
The email system according to claim 1 or 2. Further provided with an erroneous input address recording means for recording the sender's address of the e-mail when an input operation different from the input operation is performed on the sender side as a result of the request by the request means.
When a plurality of sender addresses are recorded by the erroneously input address recording means, the second transmission means is configured to transmit address information including the plurality of sender addresses to the receiver address of the e-mail. Has been,
The e-mail system according to claim 3. When the approval information indicating that the sender's address included in the address information has been approved is received from the destination side of the e-mail, the e-mail related to the sender's address is transmitted to the receiver's address. Equipped with more means,
The email system according to claim 3 or 4. When non-approved information indicating that the sender address included in the address information has not been approved is received from the destination side of the e-mail, a reception rejection address recording means for recording the sender address as a reception rejection address is provided. Further prepare
The e-mail system according to any one of claims 3 to 5.

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