JP2017028666A - Transmission email system, transmission email control device, transmission email control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission email system capable of restricting the transmission of nuisance emails without using the unique number of an IP address.SOLUTION: An acquisition unit 101 obtains an email transmitted by a communication terminal. A control unit 106 obtains user identification information to identify a communication terminal user, and controls the number of emails of which the transmission source is the user identified with the user identification information on the basis of a transmission level corresponding to terminal identification information given to a communication terminal having transmitted the email.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a transmission mail system, a transmission mail control apparatus, a transmission mail control method, and a program for transmitting electronic mail.

  In recent years, unsolicited e-mails that are sent without the consent of e-mail recipients have become a problem. For this reason, many of the received mail servers have various functions for determining whether or not the electronic mail from the outgoing mail server is a junk mail and blocking the junk mail. For example, the receiving mail server registers a sending mail server that sends a large amount of junk mail in a black list that is a list of alert sending mail servers, and electronic mail from the sending mail server registered in the black list. It has a function to restrict mail reception.

  If the incoming mail server has the above functions, an email from a general user who is not a spam mail, even if it is a spam mail, if it is an email from an outgoing mail server registered in the blacklist Even in such a case, since reception of all e-mails is restricted, there is a possibility that non-spam e-mails may not reach the recipient.

  On the other hand, Patent Document 1 describes a transmission mail server that can restrict transmission of junk mail to a reception mail server. In this outgoing mail server, the mail address and IP address of the user terminal that sent the electronic mail are acquired, and the unique number of IP addresses for each mail address (the number of different IP addresses) is obtained. When there is an email address whose unique number is greater than or equal to the threshold, the outgoing mail server is likely to have been misused by others, so it is determined that an email having the email address as a sender is spam. Restrict sending of the email.

  As a result, it is possible to reduce the number of spam mails transmitted to the received mail server, and thus it is possible to prevent registration of the outgoing mail server to the black list. Therefore, it is possible to prevent an email that is not a junk mail from reaching the recipient.

JP 2014-50057 A

  Although there is no particular problem with the electronic mail monitoring device described in Patent Document 1, it is expected that spam mail transmission methods and the like will be diversified in the future, and a technique capable of limiting the transmission of spam mail from another viewpoint is desired. ing.

  Accordingly, an object of the present invention is to provide a transmission mail system, a transmission mail control device, a transmission mail control method, and a program capable of restricting the transmission of spam mail without using a unique number of IP addresses. .

  A transmission mail system according to the present invention obtains an electronic mail transmitted from the communication terminal, and a storage unit that stores terminal identification information given to the communication terminal in association with a transmission level indicating a warning level of the communication terminal. Acquiring the user identification information for identifying the user of the communication terminal and the user identification based on the transmission level corresponding to the terminal identification information given to the communication terminal that has sent the electronic mail And a control unit for controlling the number of e-mails whose information is transmitted.

  A transmission mail control device according to the present invention transmits terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal, and an electronic mail acquired by a transmission mail server A receiving unit that receives terminal identification information assigned to the communication terminal, and a transmission level corresponding to the terminal identification information received by the terminal identification information as control information for controlling the number of e-mails to be transmitted. And a notification unit for notifying to.

  A transmission mail control method according to the present invention is a transmission mail control method performed by a transmission mail system having a storage unit that stores terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal. A step of acquiring an e-mail transmitted from the communication terminal, a step of acquiring user identification information for identifying a user of the communication terminal, and a terminal attached to the communication terminal that has transmitted the e-mail Controlling the number of e-mails sent from the user identification information based on the transmission level corresponding to the identification information.

  A program according to the present invention is a program for causing a computer connected to a storage unit to store terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal, A procedure for acquiring an e-mail transmitted from the communication terminal, user identification information for identifying a user of the communication terminal is acquired, and corresponds to the terminal identification information given to the communication terminal that has transmitted the e-mail. Based on the transmission level, the computer is caused to execute a procedure for controlling the number of e-mails transmitted from the user identification information.

  According to the present invention, it is possible to limit transmission of spam mail without using a unique number of IP addresses.

1 is an overall view showing a transmission mail system according to a first embodiment. It is a block diagram which shows the structure of a transmission mail server. It is a block diagram which shows the structure of a transmission mail control apparatus. It is a figure which shows an example of a country IP address list. It is a figure which shows an example of the transmission level list according to country. It is a flowchart for demonstrating an example of operation | movement of the transmission mail system of 1st Embodiment. It is a flowchart for demonstrating in detail the process of step S606 of FIG. It is a figure which shows an example of the relationship between a transmission level and a transmission frequency. It is a figure which shows an example of a black list. It is a figure which shows the other example of the relationship between a transmission level and a transmission frequency. It is a flowchart for demonstrating an example of operation | movement of the transmission mail system of 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to what has the same function, and the description may be abbreviate | omitted.

  FIG. 1 is an overall view showing a transmission mail system according to a first embodiment of the present invention. As shown in FIG. 1, the transmission mail system 1 includes a transmission mail server 11 and a transmission mail control device 12. The outgoing mail system 1 is connected to the user terminal 2 and the incoming mail server 3 via the Internet 10.

  The user terminal 2 is a communication terminal that sends an e-mail, and sends a connection request and an e-mail requesting establishment of a session with the sending mail server 11 to the sending mail system 1 via the Internet 10. The incoming mail server 3 receives an electronic mail from the outgoing mail system 1 via the Internet 10 and stores it in a mailbox at the destination of the electronic mail. The arrows in the figure indicate the flow of e-mail.

  FIG. 2 is a block diagram showing the configuration of the outgoing mail server 11. As shown in FIG. 2, the transmission mail server 11 includes an acquisition unit 101, a connection unit 102, a temporary storage unit 103, a maximum mail number storage unit 104, a transmission unit 105, and a control unit 106.

  The acquisition unit 101 acquires a connection request and an e-mail transmitted from the user terminal 2 to the transmission mail server 11 via the Internet 10. For example, the acquisition unit 101 is realized by a NIC (Network Interface Card) or the like. The connection request includes a user ID that is user identification information that identifies a user who is a user of the user terminal 2 and a password that is authentication information for authenticating the user. The user ID is, for example, an email address or a user name. The authentication information may be information different from the password.

  The connection unit 102 connects to the outgoing mail control device 12 and the user DB 13. For example, the connection unit 102 includes a NIC (Network Interface Card) or the like, and connects to the outgoing mail control device 12 and the user DB 13 via a network such as a LAN (Local Area Network). Here, the connection between the connection unit 102 and the user DB 13 may be a connection via a serial ATA interface, a SAS interface, or the like instead of a connection via a network. Further, in the following explanation, when the control unit 106 accesses the user DB 13 via the connection unit 102 and reads or writes data stored in the user DB 13, the point via the connection unit 102 is omitted. There is a case.

  Further, the connection unit 102 transmits transmission indicating the alertness level of the user terminal 2 as control information for controlling the number of emails transmitted from the user of the user terminal 2 that has transmitted the email acquired by the acquisition unit 101. Receive level.

  The user DB 13 is an example of a result storage unit. For example, the user DB 13 is realized by a hard disk drive, NAS (Network Attached Storage), or the like. The user DB 13 stores user information regarding users. The user information is, for example, a transmission record corresponding to a user ID, a password for authenticating the user specified by the user ID, and a transmission record corresponding to the number of transmission mails transmitted from the user. This is information that associates numbers. Further, in the user information, an excess flag indicating that transmission of an e-mail having a user ID as a transmission source is restricted may be associated with the user ID. Further, in the user information, when the user ID is not an email address, the email address is associated with the user ID.

  Specifically, the email having the user ID as the sender is an email having a mail address that is the user ID itself that identifies the user or a mail address corresponding to the user ID as the sender email address. The number of emails sent may be the number of emails from the user, or the product of the number of emails and the number of destinations of each email. In the present embodiment, it is assumed that the number of e-mails to be sent is the product of the number of e-mail bodies and the number of e-mail destinations. Here, the destination includes the destination specified in the carbon copy column and the blind carbon copy column. The number of transmission records is the product of the number of emails transmitted from the user and the number of transmissions that is a value corresponding to the transmission level indicating the alertness of the user terminal 2 of the user. In the example of FIG. 2, the user DB 13 is provided outside the transmission mail server 11, but may be built in the transmission mail server 11.

  The temporary storage unit 103 temporarily stores an electronic mail whose transmission is restricted. The maximum number-of-mails storage unit 104 stores a maximum number of mails that is a threshold for determining whether or not to limit transmission of electronic mail. For example, the temporary storage unit 103 and the maximum mail number storage unit 104 are realized by a RAM (Random Access Memory), a flash memory, a hard disk drive, or the like. The transmission unit 105 transmits an electronic mail to the received mail server 3 via the Internet 10. For example, the transmission unit 105 is realized by a NIC (Network Interface Card) or the like.

  The control unit 106 controls transmission of the email acquired by the acquisition unit 101. For example, the control unit 106 is realized by a program stored in a hard disk drive being expanded in a RAM and executed by a CPU (Central Processing Unit).

  Specifically, the control unit 106 first acquires the user ID and password in the connection request acquired by the acquisition unit 101, and collates the user ID and password with the user ID and password stored in the user DB 13. Then, the user is authenticated.

  If the authentication is successful, the control unit 106 uses the terminal identification information given to the email acquired by the acquisition unit 101 as an acquisition request for control information that controls the number of emails transmitted from the acquired user ID. A request for acquiring a transmission level corresponding to is sent to the outgoing mail control device 12 via the connection unit 102. Thereafter, when the connection unit 102 receives the transmission level for the acquisition request, the control unit 106 controls the number of emails transmitted from the user of the user terminal 2 based on the transmission level. In this embodiment, the terminal identification information is an IP (Internet Protocol) address, and the acquisition request includes the IP address.

  Specifically, the control unit 106 sets a predetermined set time (for example, 24 based on the transmission level received by the connection unit 102 and the number of transmission records corresponding to the user ID in the connection request in the user DB 13. Controls how many emails are sent within a time or 3 days).

  For example, the control unit 106 updates the number of transmission results based on the transmission level, and determines whether or not the updated number of transmission results is greater than or equal to the maximum number of emails stored in the maximum email number storage unit 104. And the control part 106 restrict | limits the transmission of the email from the user of the user terminal 2, when the transmission performance number is more than the maximum number of emails. That is, the control unit 106 temporarily stores the e-mail in the temporary storage unit 103 without transmitting the e-mail.

  The outgoing mail server 11 has an MTA (Message Transfer Agent) function for determining an appropriate transmission destination of an electronic mail and an MDA (Mail Delivery Agent) function for transmitting an electronic mail to the transmission destination. Since these functions are well known to those skilled in the art, a detailed description thereof will be omitted. The outgoing mail server 11 may have a function as a incoming mail server that receives an electronic mail from another outgoing mail server and transfers it to the user terminal.

  FIG. 3 is a block diagram showing the configuration of the outgoing mail control device 12. As shown in FIG. 2, the outgoing mail control device 12 includes a storage unit 201, a connection unit 202, and a notification unit 203.

  The storage unit 201 stores correspondence information indicating correspondence between an IP address that is terminal identification information and a transmission level that indicates the alertness level of the user terminal to which the IP address is assigned. For example, the storage unit 201 is realized by a hard disk drive, NAS (Network Attached Storage), or the like. In this embodiment, the transmission level is determined for each group that classifies IP addresses. The group indicates at least one of the country and region indicated by the IP address. Hereinafter, the group is referred to as a country or a region.

  Specifically, the storage unit 201 includes an address storage unit 211 and a transmission level storage unit 212.

  The address storage unit 211 stores a country-specific IP address list indicating correspondence between an IP address and a country code indicating a country or region which is a group of IP addresses. The country-specific IP address list is included in the correspondence information.

  FIG. 4 is a diagram showing an example of the country IP address list. The country IP address list 400 shown in FIG. 4 includes an IP address band 401 that is a range of IP addresses, and a country code 402 that indicates the country or region corresponding to the IP address of the IP address band 401.

  Returning to the description of FIG. The transmission level storage unit 212 stores a country-specific transmission level list indicating correspondence between the country code and the transmission level indicating the alertness level of the user terminal in the country or region indicated by the country code. The country-specific transmission level list is included in the correspondence information.

  FIG. 5 is a diagram illustrating an example of the country-specific transmission level list. The country-specific transmission level list 500 shown in FIG. 5 includes a country code 501 indicating a country and a region, and a transmission level 502. The transmission level 502 indicates the alert level in three stages of “HIGH”, “MIDDLE”, and “LOW” in order from the highest alert level.

  Returning to the description of FIG. The connection unit 202 connects to the outgoing mail server 11. For example, the connection unit 202 includes a NIC or the like, and connects to the transmission mail server 11 via a network such as a LAN. For example, the connection unit 202 functions as a reception unit that receives a transmission level acquisition request from the transmission mail server 11.

  The notification unit 203 uses the storage unit 201 to acquire a transmission level corresponding to the IP address in the acquisition request received by the connection unit 202, and notifies the transmission mail server 11 of the transmission level as control information. For example, the notification unit 203 is realized by a program stored in a hard disk drive being expanded in a RAM and executed by a CPU (Central Processing Unit).

  Specifically, the notification unit 203 includes a code identification unit 221 and a transmission level analysis unit 222. The code identification unit 221 acquires the country code corresponding to the IP address in the acquisition request from the address storage unit 211. The transmission level analysis unit 222 acquires the transmission level corresponding to the country code acquired by the code identification unit 221 from the transmission level storage unit 212 and notifies the transmission mail server 11 of the acquired transmission level. Even if the user ID is the same, the IP address of the user terminal 2 changes from session to session, so the transmission level may also change from session to session.

FIG. 6 is a flowchart for explaining an example of the operation of the transmission mail system of this embodiment.
First, the acquisition unit 101 of the outgoing mail server 11 receives a connection request transmitted from the user terminal 2 and outputs the connection request to the control unit 106. When the control unit 106 receives the connection request, the control unit 106 acquires a user ID and a password from the connection request. Then, the control unit 106 accesses the user DB 13 via the connection unit 102, and authenticates the user by comparing the acquired user ID and password with the user ID and password stored in the user DB 13. At this time, when the acquired user ID and password are stored in association with each other in the user DB 13, the control unit 106 determines that the authentication is successful, and the user ID and password are stored in association with each other. If not, it is determined that the authentication has failed. Here, it is assumed that the control unit 106 succeeds in user authentication. In this case, the control unit 106 connects to the user terminal 2 and constructs a session with the user terminal 2 (step S601).

  When a session is established with the user terminal 2, the control unit 106 acquires an IP address that is identification information given to the user terminal 2. For example, the control unit 106 acquires an IP address used for communication when establishing a session between the user terminal 2 and the outgoing mail server 11 (step S602).

  Thereafter, the acquisition unit 101 acquires an email from the user terminal 2 and transmits the email to the control unit 106. When receiving the electronic mail, the control unit 106 transmits an acquisition request including the IP address acquired in step S602 to the transmission mail control device 12 via the connection unit 102 (step S603). Note that the control unit 106 may acquire the IP address from the header or the like of the email received in step S603 instead of executing the process of step S602.

  The connection unit 202 of the outgoing mail control device 12 receives the acquisition request and transmits the acquisition request to the code identification unit 221. When receiving the acquisition request, the code identification unit 221 acquires a country code corresponding to the IP address in the acquisition request from the country IP address list stored in the address storage unit 211, and transmits the country code to the transmission level analysis unit 222. (Step S604).

  When receiving the country code, the transmission level analysis unit 222 acquires a transmission level corresponding to the country code from the country-specific transmission level list stored in the transmission level storage unit 212, and transmits the transmission level via the connection unit 202. It transmits to the mail server 11 (step S605).

  The connection unit 102 of the transmission mail server 11 receives the transmission level and transmits the transmission level to the control unit 106. The control unit 106 receives the transmission level, and controls the number of emails to be transmitted based on the transmission level (step S606).

  In the above operation, when the session is established in step S601, the control unit 106 allows the number of outgoing mails to be controlled so that the user specified by the user ID in the connection request transmits the number of electronic mails. You may determine whether it is a target user. For example, when the user is a target user, the user ID and a target flag indicating that the user specified by the user ID is the target user are stored in the user DB 13 in association with each other. It is determined whether or not the user is the target user by determining whether or not the target flag is associated with the user ID in the connection request. In this case, if the user is the target user, the processing after step S602 is performed.

FIG. 7 is a flowchart for explaining the processing of the control unit 106 in step S606 in more detail.
First, the control unit 106 determines whether or not an excess flag is associated with the acquired user ID in the user DB 13 (step S701).

  When the excess flag is not associated, the control unit 106 updates the number of transmission records corresponding to the acquired user ID from the user DB 13 using the transmission level received in step S606 (step S702).

  Specifically, the control unit 106 first obtains the number of emails to be sent this time by multiplying the number of email main bodies received in step S603 by the number of destinations of each email. Further, the control unit 106 obtains the current transmission record number obtained by multiplying the current transmission mail number by the transmission frequency which is a value corresponding to the transmission level. Then, the control unit 106 adds the current transmission record number to the transmission record number corresponding to the user ID, and updates the transmission record number stored in the user DB 13.

  FIG. 8 is a diagram illustrating an example of the relationship between the transmission level and the transmission frequency. In the example of FIG. 8, the transmission level 801 indicates three levels of alertness, “HIGH”, “MIDDLE”, and “LOW”, and the transmission level 802 corresponds to each alertness in descending order of alertness. Numerical values “10.0”, “5.0”, and “1.0” are shown. Information indicating the relationship between the transmission level and the transmission frequency may be set in the control unit 106 in advance, or may be stored in the maximum mail number storage unit 104 or the like.

  Note that the number of e-mail main bodies is 1 when the control unit 106 performs the processes in and after step S603 every time an e-mail is received. In addition, the number of e-mail bodies may be the number of e-mails acquired by the acquisition unit 101 between the establishment of the session and the end of the session, or the e-mail acquired by the acquisition unit 101 within a specified time. It may be the number of emails, the number of emails acquired when a predetermined time or more has elapsed since the acquisition unit 101 last acquired emails, or an email transmission instruction once by the user terminal 2 The number of e-mails acquired by the acquisition unit 101 may be used.

  When the transmission record number is updated, the control unit 106 compares the updated transmission record number with the maximum mail number stored in the maximum mail number storage unit 104 to determine whether the transmission record number is equal to or greater than the maximum mail number. Judgment is made (step S703).

  If the number of actual transmissions is less than the maximum number of emails, the control unit 106 determines that the email transmission is not restricted, and transmits the email received in step S603 via the transmission unit 105 (step S704). ), The process is terminated.

  When the transmission record number is equal to or greater than the maximum number of emails, the control unit 106 extracts emails exceeding the maximum number of emails from the emails received in step S603 and associates them with the user ID and the transmission level. Temporarily stored in the temporary storage unit 103. Then, the control unit 106 transmits an email other than the email temporarily stored in the temporary storage unit 103 via the transmission unit 105 (step S705). Note that extraction methods for extracting e-mails include a method of extracting e-mail creation date and time of sending instruction in order from the earliest date, a method of random extraction, and the like, but are not limited to these extraction methods.

  Thereafter, the control unit 106 stores an excess flag in association with the user ID (step S706), and ends the process.

  If there is an excess flag in step S701, the control unit 106 temporarily stores the e-mail received in step S603 in the temporary storage unit 103 in association with the user ID and the transmission level (step S707), and ends the process. .

  In the operation described above, in step S701, the control unit 106 determines whether or not the number of actual transmissions corresponding to the user ID is equal to or greater than the maximum number of mails, instead of whether or not the excess flag is associated with the user ID. May be. In this case, when the transmission record number is less than the maximum mail number, step S702 is executed, and when the transmission record number is equal to or greater than the maximum mail number, step S707 is executed.

  If it is determined in step S704 that the number of actual transmissions is greater than or equal to the maximum number of emails, the control unit 106 associates excess information indicating that the number of actual transmissions of email exceeds the maximum number of emails with the user ID. The user terminal 2 may be notified using an e-mail addressed to an e-mail address that is a contact address stored in the DB 13. Excess information is restriction information indicating that sending of e-mail is restricted, and the number of temporarily saved e-mails (that is, the number of e-mails that have not been sent) It may include at least one of deletion information and procedure information indicating a cancellation procedure for canceling restrictions on transmission of e-mail. The procedure information indicates, for example, a reset procedure for resetting an excess flag or the number of transmission records as a cancellation procedure, and specifically includes a URL of a procedure site for performing the reset procedure online.

  The reset procedure includes, for example, user authentication using a user ID and password on the procedure site and another user authentication (for example, authentication based on whether or not a combination of a question and an answer set in advance by the user matches) If the authentication is successful, the password is changed, and the temporarily stored e-mail list is sent to the user terminal. The e-mail is different from the e-mail sent by the user to the user. Is deleted, and then the excess flag and the actual number of transmissions are reset.

  In step S705, e-mails exceeding the maximum number of e-mails are temporarily stored and not transmitted, but all e-mails may be temporarily stored, or all e-mails may be transmitted. Also good. Even when all the e-mails are transmitted, the excess flag is stored, and the e-mails acquired thereafter are not transmitted, so the number of e-mails to be transmitted is limited.

  Further, it is desirable that the control unit 106 resets the excess flag and the number of actual transmissions every predetermined set time (for example, 24 hours, 3 days, etc.). In this case, after resetting the excess flag and the number of transmission records, the control unit 106 obtains, for each user ID temporarily stored in the temporary storage unit 103, an electronic mail corresponding to the user ID acquired by the acquisition unit 101. It is desirable to perform the above operation by regarding it as mail. At this time, the control unit 106 uses the transmission level associated with the user ID temporarily stored in the temporary storage unit 103.

Next, a specific example will be described.
(First example)
The number of transmission records stored in the user DB 13 (hereinafter referred to as the number of transmission records until the previous time) is 900, the number of transmission mails this time is 100, the transmission frequency corresponding to the transmission level is 5.0, and the maximum number of mails is 1000. Suppose there is.
In the above example,
Number of actual transmissions this time = 100 (number of mails transmitted this time) × 5.0 (frequency of transmission) = 500
Updated number of actual transmissions = 900 (number of actual transmissions up to the previous time) +500 (number of actual transmissions) = 1400
So that
Number of transmissions updated (1400)> Maximum number of emails (1000)
It becomes. Therefore, the number of excess transmission mails is calculated as follows: excess transmission mails number = 1400 (updated transmission record number) −1000 (maximum mail number) = 400
Defined as
Number of e-mails to be temporarily stored: 400 (number of over-sent mails) /5.0 (current transmission frequency) = 80
Number of e-mails to be sent: 100 (number of e-mails sent this time) −80 (number of e-mails to be temporarily saved) = 20
It becomes.

(Second example)
Assume that the number of past transmissions up to the previous time is 999, the number of outgoing mails is 1, the transmission frequency corresponding to the transmission level is 5.0, and the maximum number of mails is 1000.
In the above example,
Number of actual transmissions this time = 1 (number of mails transmitted this time) × 5.0 (frequency of transmissions) = 5
Updated number of transmission results = 999 (number of transmission results up to the previous time) +5 (number of current transmission results) = 1004
So that
Number of transmission records updated (1004)> Maximum number of emails (1000)
It becomes. Therefore, since the number of excess transmission mails is 4, the number of emails to be temporarily stored is 0.8. In such a case, you can send the email by rounding up the number of emails to be saved primarily, or you can temporarily save the email by rounding down the number of emails to be saved temporarily. May be.

(Third example)
In the second example, when the e-mail is temporarily stored, since the e-mail is not actually transmitted, the actual number of transmission results remains the number of transmission results up to the previous time. Therefore, the control unit 106 does not need to store the excess flag by returning the updated transmission record number to the previous transmission record number.

At this time, when the session is once disconnected and then the session is established with the same user ID, it is assumed that the number of transmission mails this time is 1, and the transmission frequency corresponding to the transmission level is 1.0. in this case,
Number of actual transmissions = 1 (number of emails transmitted this time) × 1.0 (frequency of transmission) = 1
Updated number of transmission results = 999 (number of transmission results up to the previous time) +1 (number of current transmission results) = 1000
So that
Number of updated transmissions (1000) = Maximum number of emails (1000)
It becomes. Accordingly, since the number of excess transmission mails is 0, the number of emails to be temporarily stored is 0 and the emails are transmitted, but the number of actual transmissions exceeds the maximum number of emails. Will be memorized. This example means that even if an e-mail cannot be transmitted in one country, an e-mail may be transmitted in another country.

  As described above, according to the present embodiment, the number of e-mails to be transmitted within a set time is controlled based on the transmission level corresponding to the IP address assigned to the user terminal that sent the e-mail. Therefore, it is possible to restrict transmission of spam mail without using a unique number of IP addresses.

(Second Embodiment)
The configuration of the transmission mail system of this embodiment is the same as that of the first embodiment, but the transmission level acquisition method is different from that of the first embodiment.

  In the present embodiment, the transmission level is determined not only according to the country code of the IP address but also according to whether or not the IP address is a specific IP address that is predetermined specific identification information. The specific IP address indicates, for example, that the alarm level of the user terminal to which the specific IP address is assigned is very high.

  Specifically, the address storage unit 211 or the transmission level storage unit 212 includes, in addition to the country-specific IP address list or the country-specific transmission level list, a black list indicating the relationship between the specific IP address and the transmission level, and a specific country. And a specific country code which is a country code indicating. The specific country code indicates, for example, the home country, that is, the country or region where the outgoing mail system is located. The black list and the specific country code are included in the correspondence information. In the following, it is assumed that the black list and the specific country code are stored in the transmission level storage unit 212.

  FIG. 9 is an example of a black list. In the black list 900 shown in FIG. 9, each specific IP address 901 is associated with a transmission level 902 indicating “CRITICAL” having a higher alertness level than “HIGH”.

  FIG. 10 is a diagram illustrating an example of the relationship between the transmission level and the transmission frequency according to the present embodiment. In the example of FIG. 10, the transmission level 811 indicates the four levels of alertness of “CRITICAL”, “HIGH”, “MIDDLE”, and “LOW”. Numerical values “100.0”, “10.0”, “5.0”, and “1.0” corresponding to are shown. As described above, it is desirable that the transmission frequency corresponding to the transmission level “CRITICAL” included in the black list is particularly larger than other transmission frequencies.

  FIG. 11 is a flowchart for explaining an example of the operation of the transmission mail system of this embodiment. The processing from step S601 to S604 is the same as the processing of the first embodiment described with reference to FIG. However, in step S604, the code identification unit 221 transmits the IP address in the acquisition request to the transmission level analysis unit 222 in addition to the country code.

  When step S604 ends, the transmission level analysis unit 222 receives the country code and the IP address, and determines whether the country code is a specific country code stored in the transmission level storage unit 212 (step S611).

  If the country code is not a specific country code, the transmission level analysis unit 222 acquires the transmission level corresponding to the received country code from the country-specific transmission level list stored in the transmission level storage unit 212, and the transmission level is connected. It transmits to the transmission mail server 11 via the part 202 (step S612). Thereafter, step S606 is executed.

  On the other hand, when the country code is a specific country code, the transmission level analysis unit 222 determines whether the IP address is included as a specific IP address in the black list stored in the transmission level storage unit 212. When the IP address is included as the specific IP address, the transmission level analysis unit 222 acquires the transmission level corresponding to the specific IP address from the black list. When the IP address is not included as the specific IP address, the transmission level analysis unit 222 acquires the transmission level with the lowest alertness level. Then, the transmission level analysis unit 222 transmits the acquired transmission level to the transmission mail server 11 via the connection unit 202 (step S613). Thereafter, step S606 is executed.

  In step S613, the transmission level analysis unit 222 may acquire the transmission level with the lowest alert level from the country IP address list, or include the transmission level with the lowest alert level in the black list. The lowest transmission level may be obtained from the black list.

  As described above, also in the present embodiment, the number of e-mails to be transmitted is controlled based on the transmission level corresponding to the IP address assigned to the user terminal that sent the e-mail. Even if it is not used, it is possible to restrict transmission of spam mail.

  In addition, since the transmission level changes depending on whether the IP address is a specific IP address, it is possible to efficiently limit the number of e-mail transmissions from users who frequently send spam mails.

  In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

  For example, the functions of the transmission mail server 11 and the transmission mail control device 12 are such that a program for realizing the functions is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in the computer. It may be realized by reading and executing.

  The outgoing mail server 11 and the outgoing mail control device 12 may be integrated.

  In addition, each list, such as country IP address list, country transmission level list, black list, and the relationship between transmission level and transmission frequency, information obtained during the operation of email service, information security industry reports, etc. It is desirable to create it based on it and update it at a predetermined timing. Further, in each list, if possible, a plurality of lists may be combined into one list. Each list is described in a table format in the description of each embodiment and drawing, but may be in other formats such as a database format.

DESCRIPTION OF SYMBOLS 1 Transmission mail system 2 User terminal 3 Reception mail server 11 Transmission mail server 12 Transmission mail control apparatus 101 Acquisition part 102 Connection part 103 Temporary preservation | save part 104 Maximum mail number preservation | save part 105 Transmission part 106 Control part 201 Storage part 202 Connection part 203 Notification Section 211 Address storage section 212 Transmission level storage section 221 Code identification section 222 Transmission level analysis section

Claims (10)

A storage unit for storing terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal;
An acquisition unit for acquiring an e-mail transmitted from the communication terminal;
User identification information for identifying a user of the communication terminal is acquired, and based on a transmission level corresponding to the terminal identification information given to the communication terminal that has transmitted the electronic mail, the user identification information is set as a transmission source. And a control unit that controls the number of e-mails to be transmitted.   The transmission mail system according to claim 1, wherein the transmission level is determined for each group for classifying the terminal identification information.   The outgoing mail system according to claim 2, wherein the group indicates at least one of a country and a region. The transmission level is further determined according to whether the terminal identification information is predetermined specific identification information,
When the terminal identification information indicates the home country, the control unit controls the number of emails to be transmitted based on the transmission level determined according to whether the terminal identification information is the specific identification information. The transmission mail system according to claim 3, wherein, when the terminal identification information does not indicate a home country, the number of emails to be transmitted is controlled based on the transmission level determined for each group. Results obtained from the user identification information, the number of transmitted emails transmitted from the user identified by the user identification information, and the value corresponding to the number of transmitted emails and the transmission level It further has a record storage unit that stores the number in association with each other,
5. The control unit according to claim 1, wherein the control unit controls the number of emails to be transmitted within a specified time based on the transmission level and the actual number corresponding to the acquired user identification information. The outgoing mail system according to item 1.   When the acquisition unit acquires the electronic mail, the control unit updates the actual number based on the electronic mail and the transmission level. When the updated actual number is equal to or greater than a threshold, the control unit 6. The transmission mail system according to claim 5, wherein the number of the e-mails to be transmitted is controlled by restricting the transmission of the e-mail as a transmission source.   When the updated number of achievements is equal to or greater than the threshold, the control unit cancels the transmission of the e-mail to the communication terminal that has transmitted the e-mail acquired by the acquisition unit and the restriction. The transmission mail system according to claim 6, wherein a restriction notification indicating a cancellation procedure is transmitted. A storage unit for storing terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal;
A receiving unit that receives the terminal identification information given to the communication terminal that has sent the e-mail acquired by the sending mail server;
A transmission mail control device comprising: a notification unit that notifies the transmission mail server of a transmission level corresponding to the terminal identification information received by the terminal identification information as control information for controlling the number of emails to be transmitted. A transmission mail control method performed by a transmission mail system having a storage unit that stores terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal,
Obtaining an email sent from the communication terminal;
Obtaining user identification information for identifying a user of the communication terminal;
A step of controlling the number of e-mails sent from the user identification information based on the transmission level corresponding to the terminal identification information given to the communication terminal that sent the e-mail. Control method. A program for causing a computer connected to a storage unit to store terminal identification information given to a communication terminal in association with a transmission level indicating a warning level of the communication terminal,
A procedure for obtaining an e-mail sent from the communication terminal;
User identification information for identifying a user of the communication terminal is acquired, and based on a transmission level corresponding to the terminal identification information given to the communication terminal that has transmitted the electronic mail, the user identification information is set as a transmission source. And a program for causing a computer to execute a procedure for controlling the number of e-mails to be transmitted.

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