JP2019022123A - E-mail transmission control device, transmission control method, and transmission control program - Google Patents

Abstract

To determine whether transmission based on various conditions is possible at the time of sending mail so as to suppress delays caused by an administrator or the like.SOLUTION: A transmission control device includes verification means that acquires a mail condition indicated by a ticket attached to a received e-mail, determines that the e-mail can be transmitted when the e-mail satisfies the e-mail condition and determines that the e-mail cannot be transmitted when the e-mail does not satisfy the e-mail condition and transmission determination means that transmits the e-mail determined to be transmitted by the verification means to a transmission destination address specified in the e-mail and does not transmit the e-mail determined not to be transmitted to the transmission destination address.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an e-mail transmission control apparatus, a transmission control method, and a transmission control program, and in particular, an e-mail transmission control apparatus, a transmission control method, and a transmission capable of flexibly determining whether or not to transmit an e-mail. It relates to the control program.

  Patent Document 1 discloses a ticket-based closed mail transfer system that determines whether or not an e-mail can be transmitted so that a member can send and receive an e-mail but not a non-member. This system has a mechanism for confirming a sender of an electronic mail by using the ticket by attaching the encrypted electronic mail address and mailer information to the electronic mail.

JP 2009-104501 A

  The system disclosed in Patent Document 1 only determines whether transmission is possible or not based on transmission source confirmation, and cannot be determined based on various conditions. Other than this, the system that forwards e-mails is based on the rules defined in advance in the system based on the e-mail attributes, for example, the destination address and the size of the attached file of the e-mail. In other cases, it may be determined whether transmission is possible. In this case, since the same and fixed rule is applied to all users, determination based on various conditions cannot be performed.

  Further, when sending an e-mail, it may be possible to inquire of an administrator or the like whether the e-mail can be sent. However, in this case, transmission of the e-mail is delayed due to the time required for the manager's decision, information collection and input operation. Furthermore, when the manager or the like is busy or absent, there is a risk of significant delay.

  The present invention solves the above-described problem, and can control whether or not transmission can be performed according to various conditions at the time of transmission of an electronic mail while suppressing the risk of delay caused by an administrator or the like. The purpose is to provide.

  The transmission control apparatus according to one embodiment of the present invention acquires a mail condition indicated by a ticket attached to a received electronic mail, and can transmit if the electronic mail satisfies the mail condition. And the verification unit that determines that the e-mail is determined to be transmittable to the destination address specified in the e-mail, and the e-mail that is determined to be unsendable is the destination address Transmission determination means for not transmitting.

  The transmission control method according to one embodiment of the present invention acquires a mail condition indicated by a ticket attached to a received electronic mail, and can transmit if the electronic mail satisfies the mail condition. The e-mail that has been determined to be sendable is transmitted to the destination address specified in the e-mail, and the e-mail that has been determined to be unsendable is not transmitted to the destination address.

  The transmission control program according to one embodiment of the present invention acquires a mail condition indicated by a ticket attached to a received e-mail, and can transmit if the e-mail satisfies the e-mail condition. The process determines that the e-mail that has been determined to be sent is sent to the destination address specified in the e-mail, and the computer does not send the e-mail that has been determined not to be sent to the destination address. Let

  According to the present invention, an e-mail transmission control apparatus can execute transmission / rejection determination based on various conditions while transmitting an e-mail with a delay caused by an administrator or the like. Here, the delay caused by the manager or the like is, for example, a delay in decision of the manager, absence from the desk, or absence.

FIG. 1 is a diagram illustrating a configuration of a transmission control apparatus 10 according to the first embodiment. FIG. 2 shows an example of a ticket issuance application mail transmitted by the user terminal device 31. FIG. 3 shows an example of a ticket issue response mail transmitted by the administrator terminal 32. FIG. 4 shows an example of the structure of a ticket generated by the ticket issuing unit 14. FIG. 5 is a diagram showing an outline of the flow of information related to ticket issuance. FIG. 6 shows an example of mail transmitted by the user terminal 31. FIG. 7 is a diagram showing an outline of the flow of information related to mail transmission. FIG. 8 is a configuration diagram of the computer device 60. FIG. 9 is a flowchart showing a ticket issuing process. FIG. 10 is a flowchart showing mail transmission processing. FIG. 11 is a diagram illustrating a configuration of the transmission control apparatus 10 according to the second embodiment.

<First embodiment>
<Overview>
Users who want to send e-mails (hereinafter simply abbreviated as e-mails) specify the conditions for e-mails that they want to be authorized to send before sending e-mails, and control the issuance of tickets that indicate sending rights Apply to the device 10. The mail condition (hereinafter simply abbreviated as mail condition) is a group of attribute values that can be determined from the mail. For example, the type of file that may be attached / prohibited to the mail, the maximum size of the attached file Or a destination domain where transmission is allowed / prohibited. Here, the file type is, for example, a distinction between a document, a spreadsheet, and an image indicated by a file name extension.

  The transmission control device 10 inquires of an administrator or the like whether or not the user can be given the authority to transmit an email with the email condition. If permitted, the transmission control device 10 generates a ticket in which the email condition is described to the user. Send.

  When the user receives the ticket, it saves it until the time of mail transmission. At the time of mail transmission, the user creates a mail at the user terminal device 31, assigns the ticket to the mail, and transmits it toward the destination address. The mail passes through the transmission control device 10. When the mail protocol is SMTP (Simple Mail Transfer Protocol), the user terminal device 31 corresponds to MUA (Mail User Agent), and the transmission control device 10 corresponds to MTA (Mail Transfer Agent).

  The transmission control apparatus 10 determines whether or not the mail satisfies the mail conditions described in the assigned ticket. The transmission control apparatus 10 transmits to the destination address if the mail satisfies the mail condition, but does not transmit to the destination address if the mail is not satisfied, for example, discards it.

<Configuration>
FIG. 1 is a diagram illustrating a configuration of a transmission control apparatus 10 according to the present embodiment. The transmission control device 10 is included in a mail transmission / reception device 20 that is a so-called mail server device, together with a mail reception unit, for example, a mail reception unit 21 and a mail transmission unit, for example, a mail transmission unit 22.

  Here, the mail receiving unit 21 receives mail from the user terminal device 31, the administrator terminal device 32, or another mail transmitting / receiving device 20. Further, the mail receiving unit 21 guarantees the connection source by the mail address and password by authentication. On the other hand, the mail transmission unit 22 transmits mail to the user terminal device 31, the administrator terminal device 32, or another mail transmission / reception device 20. The mail receiving unit 21 and the mail transmitting unit 22 are generally provided in a mail server device.

  The transmission control apparatus 10 includes a ticket issuing unit such as a ticket issuing unit 14, a verification receiving unit such as a verification receiving unit 16, a verification unit such as a verification unit 18, and a transmission determination unit such as a transmission determination unit 19.

<Ticketing related configuration>
The ticket issuing unit 14 receives a ticket issue application mail from the user terminal device 31. The ticket issuance application mail is transmitted to an address for ticket issuance application, for example, and is delivered to the ticket issuing unit 14. The ticket issuance application mail describes the mail conditions desired by the user.

  FIG. 2 shows an example of a ticket issuance application mail transmitted by the user terminal device 31. In the example of FIG. 2, the mail conditions desired by the user are the destination address (xyz@zzz.zzz.zzz.com), the maximum size of the mail attachment file (30 MB), and the type of file to be attached ( .doc and .zip). The mail conditions may include various conditions such as the number of mail destinations and “including a specific character string”.

  The ticket issuing unit 14 transfers the received issue application mail to the administrator terminal device 32. This is because the administrator who operates the administrator terminal device 32 is requested to determine whether or not the ticket is issued. Here, the administrator is, for example, the boss of the user who sent the issuance application mail, understands the user's work contents and the work situation at the time of the application, and the mail conditions described in the issuance application mail are appropriate. It can be determined whether or not.

  The administrator transmits a ticket issuance response mail notifying the result of the determination to the ticket issuing unit 14. The ticket issuance response mail includes whether or not ticket issuance is permitted (OK or NG), and mail conditions when it is determined that issuable, for example, in the mail text. The e-mail conditions may be the same as those described in the issuance application e-mail, but the range of transmission permitted by the administrator's judgment may be narrowed or widened. For example, even if a user has applied for a mail attachment size of 30MB as an email condition, if the administrator thinks that it is not necessary to have such a large file, the ticket issuance response email contains the email attachment file An email condition indicating a size of 10 MB may be included.

  FIG. 3 shows an example of a ticket issuance response mail transmitted by the administrator terminal device 32. In the first line of the mail body, the determination result that the ticket can be issued is described, and in the second to fourth lines, the mail conditions for the permitted mail are described. In the mail condition of this example, the maximum size of the mail attachment file is 30 MB (second line), the domain name permitted to be transmitted is zzz.zzz.zzz.com (third line), and may be attached. The file type is .doc and .zip (line 4). In this example, the applicant thought that it would be sufficient to send email only to xyz@zzz.zzz.zzz.com, but the administrator thinks that there is a possibility that the administrator may send it to other people in the domain. , @ Zzz.zzz.zzz.com is allowed to send to anyone in the domain. That is, in this example, the administrator relaxes the applied mail conditions and expands the range in which mail transmission is permitted.

  When the ticket issuing unit 14 receives a ticket issuance response mail whose determination result is “OK”, the ticket issuing unit 14 generates a ticket.

  FIG. 4 shows an example of the structure of a ticket generated by the ticket issuing unit 14. The ticket indicates basic information and mail conditions. The basic information is used to determine the validity of the ticket. The verification unit 18 to be described later determines that the mail can be transmitted when the ticket is valid and the mail to which the ticket is attached satisfies the mail condition.

  The basic information indicates the applicant address, application date and time, issuer address, and expiration date. The applicant address is the sender address of the ticket issuance application mail (the address of the user terminal device 31 of the user who applied). The issuer address is the sender address of the ticket issue response mail (the address of the administrator terminal device 32). Note that the applicant address and the issuer address are described in plain text in the example of FIG. 4, but may be hash values. Since the ticket is verified in the transmission control apparatus 10, the hash function is managed and referenced only in the transmission control apparatus 10.

  The expiration date is a period during which the ticket is valid, for example, 24 hours after the ticket is generated. This period may be specified uniformly by the transmission control apparatus 10 or may be specified by the administrator using a ticket issuance response mail.

  An identifier is given to the ticket. For example, the ticket identifier may be generated by encrypting the contents of the ticket, or may be generated by the ticket issuing unit 14 using other logic. The ticket includes a part of the ticket, for example, a part that can be identified as a ticket, and identification data of the transmission control apparatus 10 that has issued the ticket. Later, the verification reception unit 16 determines that the ticket is a ticket issued by the transmission control device 10 based on the identification data.

  The ticket issuing unit 14 generates a ticket as a file for each ticket. The ticket file contains basic information and email conditions. The ticket issuing unit 14 encrypts the ticket. The encryption method is not limited, but for example, a common key method may be used. The reason is that the transmission controller 10 also decodes. The user attaches the ticket to the mail to be transmitted and transmits it to the transmission control device 10 when the mail is transmitted later.

  Finally, the ticket issuing unit 14 attaches the generated ticket to the result notification mail and transmits it to the applicant address. The user keeps the issued ticket in, for example, the user terminal device 31 until later mail transmission. Note that the ticket issuing unit 14 may issue a ticket in a format that the user downloads from a designated homepage.

  When the ticket issuing unit 14 receives a ticket issuance response mail whose determination result is not issuable (NG), the ticket issuing unit 14 does not generate a ticket and sends a result notification mail indicating that the ticket is rejected to the sender address of the ticket issuance application mail. To do.

  FIG. 5 is a diagram showing an outline of the flow of information related to ticket issuance. In the figure, the arrow in (a) shows the flow of the ticket issuance application mail. In the figure, the arrow in (b) indicates the flow of the ticket issue response mail. In the figure, the arrow in (c) indicates the flow of the response notification mail.

<Mail transmission related configuration>
The user who has received the ticket attaches the ticket to the mail to be transmitted and transmits the mail from the user terminal device 31. FIG. 6 shows an example of mail transmitted by the user terminal device 31. This e-mail address is xyz@zzz.zzz.zzz.com, and there are three files, a plan book.zip (27MB), a list of related parties.doc (2MB), and a ticket (0.1KB). It is attached.

  This mail is input to the verification receiving unit 16 via the mail receiving unit 21 ((a) of FIG. 7). FIG. 7 is a diagram showing an outline of the flow of information related to mail transmission.

  The verification receiving unit 16 determines whether a ticket is attached to the e-mail issued by the own apparatus. If the ticket issued by the device itself is not attached, the verification receiving unit 16 determines that the mail cannot be transmitted. The e-mail that is determined not to be transmitted is refused to be transmitted and is returned to the user terminal device 31 or discarded. When the ticket issued by the own apparatus is attached, the verification receiving unit 16 decrypts the ticket and outputs the mail to the verification unit 18 ((b) of FIG. 7).

  The verification unit 18 first confirms the validity of the ticket. For example, the verification unit 18 performs the following confirmation, and determines that the ticket is valid if all can be confirmed, and determines that the ticket is not valid if even one cannot be confirmed. If the ticket is not valid, the verification unit 18 determines that mail transmission is not possible.

  a1) The verification unit 18 confirms whether the transmission source address (address of the user terminal device 31) that sent the mail matches the applicant address described in the ticket. If the applicant address is hashed, the verification unit 18 also performs the confirmation by hashing the transmission source address.

  a2) The verification unit 18 confirms whether the issuer address matches the administrator's address (the address of the administrator terminal device 32).

  a3) The verification unit 18 checks whether the current time is within the expiration date.

  If the ticket is valid, the verification unit 18 analyzes the mail data and verifies whether the mail satisfies the mail condition. For example, the verification unit 18 performs the following confirmation, and determines that the email satisfies the email condition if all of the verification is possible, and determines that the email is not satisfied if even one cannot be confirmed.

  b1) The verification unit 18 compares the size of the attached file with the maximum size of the attached file specified by the mail condition, and confirms whether the former does not exceed the latter. When there are a plurality of attached files, the verification unit 18 compares the total size of the attached files with the maximum size of the attached file specified by the mail condition.

  b2) The verification unit 18 compares the type of the attached file with the type of the file that can be attached specified by the mail condition, and confirms whether they match. Alternatively, the verification unit 18 compares the type of the attached file with the type of file that is prohibited from attachment specified by the mail condition, and confirms whether or not they match.

  b3) The verification unit 18 compares the address of the mail with the address or domain permitted for transmission specified in the mail condition, or the addresses match. Make sure the address is in the domain. Alternatively, the verification unit 18 compares the address of the mail with the address or domain where transmission specified in the mail condition is prohibited, or the addresses do not match. Make sure the address is not within the domain.

  For example, if the mail condition is as shown in FIG. 4, the verification unit 18 determines that the mail in FIG. 6 satisfies the mail condition. For example, in the mail condition of FIG. 4, the size of the attached file of the mail is 30 MB, whereas in the mail of FIG. 6, the total size of the attached file is 29 MB (27 MB + 2 MB).

  The verification unit 18 determines that transmission is possible if the mail satisfies the mail condition, and determines that transmission is not possible if the mail does not satisfy the mail condition. After the determination, the verification unit 18 outputs the determination result and the mail to the transmission determination unit 19 ((c) in FIG. 7).

  The transmission determination unit 19 transmits the mail determined to be transmittable to the destination address via the mail transmission unit 22 ((d) in FIG. 7). At this time, the transmission determination unit 19 deletes the ticket from the mail. Further, the transmission determination unit 19 rejects the transmission of the mail determined to be unsuccessful and returns it to the transmission source address or discards it.

  Here, the ticket issuing unit 14, the verification receiving unit 16, the verification unit 18, and the transmission determination unit 19 of the transmission control apparatus 10 are configured by a logic circuit or a dedicated processor and firmware.

  The ticket issuing unit, the verification receiving unit, the verification unit 11 and the transmission control unit of the transmission control apparatus 10 may have other configurations that perform the same function.

  Further, the transmission control device 10 may be configured by a computer device 60. FIG. 8 is a configuration diagram of the computer device 60. The computer device 60 includes a processor 61, a main storage unit 63, and an external storage device 62 that are connected to each other via a bus 64. The processor 61 reads and writes data from and to the main storage unit 63 and the external storage device 62 via the bus 64.

  Further, the processor 61 executes a program 65 stored in the main storage unit 63. Note that the program 65 is initially stored in the external storage device 62, and the processor 61 may load the main storage unit 63 from the external storage device 62 when the computer device 60 is initially set.

  Here, the main storage unit 63 is a semiconductor memory device. The external storage device 62 is a storage device such as an HDD (Hard Disk Drive) or an SDD (Solid State Drive).

  The processor 61 of the transmission control apparatus 10 functions as the ticket issuing unit 14, the verification receiving unit 16, the verification unit 18, and the transmission determination unit 19 by executing the program 65. That is, by executing the program 65, the processor 61 executes processing performed by the ticket issuing unit 14, the verification receiving unit 16, the verification unit 18, and the transmission determination unit 19.

<Operation>
FIG. 9 is a flowchart showing a ticket issuing process. The data flow at this time is as shown in FIG.

  First, a user who wishes to issue a ticket transmits a ticket issuance application mail from the user terminal device 31 to an e-mail address for ticket issuance application. At this time, the user writes the desired mail condition in the text of the ticket issuance application mail. The ticket issuing unit 14 of the transmission control device 10 receives the ticket issue application mail (S1) and transfers it to the administrator terminal device 32 (S2). The transfer destination administrator terminal device 32 is determined in advance corresponding to, for example, the user terminal device 31 that has transmitted the ticket issuance application mail.

  The administrator who operates the administrator terminal device 32 that has received the ticket issue application mail determines whether the ticket is issued in consideration of the sender of the ticket issue application mail and the desired mail conditions. Determine acceptable email conditions. After the determination, the administrator creates a ticket issuance response mail in a format that is replied to the forwarded ticket issuance application mail, and transmits it to the ticket issuing unit 14. The ticket issuance response mail includes, in a sentence, whether or not the requested ticket issuance is permitted and when it is permitted.

  The ticket issuing unit 14 receives the ticket issuance response mail (S3), and if the text of the ticket issuance response mail indicates that the ticket can be issued (YES in S4), generates and encrypts the ticket (S5) Is transmitted to the user terminal device 31 of the ticket issue application mail transmission source (S6). At this time, the ticket issuing unit 14 creates a ticket notification mail in a format that is replied to the transmitted ticket issuance application mail, and attaches the ticket to the ticket notification mail and transmits it to the user terminal device 31.

  If the text of the ticket issuance response mail indicates that the ticket is not issued (NO in S4), the ticket issuing unit 14 creates a ticket notification e-mail notifying that the ticket issuance has been rejected, and issues the ticket issuance application. It transmits to the user terminal device 31 of mail transmission origin (S7).

  FIG. 10 is a flowchart showing mail transmission processing. The data flow at this time is as shown in FIG.

  At the time of mail transmission, the user attaches a ticket to the mail and transmits it from the user terminal device 31 to the destination mail address. The mail is transmitted to the mail transmitting / receiving apparatus 20 which is a mail server apparatus, and is received by the verification receiving unit 16 (S11). If the ticket is attached to the mail (YES in S12), the verification receiving unit 16 decrypts the ticket (S13) and outputs it to the verification unit 18. The verification unit 18 that has received the plaintext ticket extracts basic information (see FIG. 4) from the ticket and determines the validity (S14). If the ticket is valid (YES in S15), the verification unit 18 extracts the mail condition from the ticket (see FIG. 4), and determines whether the mail satisfies the mail condition (S16). If the mail satisfies the mail condition (YES in S17), the verification unit 18 determines that the mail can be transmitted, and notifies the transmission determination unit 19 to that effect. Upon receiving this notification, the transmission determination unit 19 transmits the mail toward the destination address (S18). At this time, the transmission determination unit 19 deletes the attached ticket.

  When the ticket is not attached to the mail (NO in S12), the verification receiving unit 16 determines that the mail cannot be transmitted and notifies the transmission determining unit 19 of the mail. Further, when the ticket is not valid (NO in S15) and when the mail does not satisfy the mail condition (NO in S17), the verification unit 18 determines. The mail is determined not to be transmitted and is notified to the transmission determination unit 19. Upon receiving these notifications, the transmission determination unit 19 rejects the transmission of the mail (S19). In this case, the transmission determination unit 19 discards this mail or returns it to the user terminal device 31 that is the transmission source.

<Modification of the present embodiment>
In the above description, the ticket issuing unit 14 generates and encrypts the ticket as a file in which basic information and mail conditions are described. Then, the user attaches the ticket to the mail and transmits it, and the verification unit 18 acquires the basic information and the mail condition by reading the file.

  On the other hand, the ticket issuing unit 14 may generate a ticket as a character string representing a ticket identifier. In this case, the ticket issuing unit 14 stores the basic information of the ticket and the mail condition in a ticket storage area (not shown) in the transmission control device 10 in association with a ticket identifier that is unique in the transmission control device 10. The user transmits the ticket identifier to the transmission control apparatus 10 in the mail text, signature part, subject, etc. to be transmitted when the mail is transmitted later. The verification unit 18 acquires the basic information and the mail condition by reading the ticket storage area using the ticket identifier as a key.

  In this case, since the contents of the ticket are not transmitted outside the transmission control apparatus 10, the necessity for encryption is low as compared with the file method.

  Therefore, the ticket is attached to the mail as a file or written as a character string in the mail body. Attaching a ticket to a mail as a file, writing a ticket identifier as a character string in the mail, and the like are collectively referred to as giving a ticket to the mail.

  The basic information and the mail conditions are described in a ticket file or stored in a ticket storage area (not shown) in the transmission control apparatus 10 in association with a ticket identifier. These are collectively referred to as basic information and e-mail conditions shown in a ticket, or a ticket shows basic information and e-mail conditions.

<Effect>
The transmission control apparatus 10 according to the present embodiment can execute the transmission permission / inhibition determination based on various conditions while transmitting a mail while suppressing a delay caused by an administrator or the like. The reason is that the verification unit 18 acquires the mail condition indicated by the ticket attached to the mail, and determines that transmission is possible if the electronic mail satisfies the mail condition, and transmission is impossible if the electronic mail does not satisfy the mail condition. Tickets are issued prior to the transmission of e-mails and can contain various information. By giving this ticket to an email when sending an email, the user can send emails with various email conditions that are difficult to control with an inflexible email server filter by suppressing the delay caused by the administrator when sending email. . That is, the transmission control apparatus 10 according to the present embodiment can specify various different filter conditions for each user, and even for the same user, for each mail.

  The transmission control apparatus 10 according to the present embodiment can perform safe mail transmission control. The reason is that the verification unit 18 verifies the validity of the ticket so that, for example, the ticket of another person cannot be stolen, and further, the mail condition is encrypted or stored in the apparatus. This is because it prevents eavesdropping and falsification of email conditions.

  The transmission control apparatus 10 according to the present embodiment can be easily introduced. The reason is that it can be easily incorporated into the existing mail transmitting / receiving apparatus 20.

  The transmission control apparatus 10 according to the present embodiment can also permit mail relay. The mail transmission / reception device 20 often has a function of rejecting third-party relay so as not to be a stepping stone for mail relay. The third party relay is a mail transmission from an external domain or an external IP (Internet Protocol) terminal device to an external domain server. In the transmission control device 10, a ticket is attached to the mail, and if the validity of the ticket can be confirmed, delivery can be permitted even by third party relay. This property is effective in cases such as when mail is sent to the customer at the destination but delivery is blocked by the filter function.

<Second Embodiment>
FIG. 11 is a diagram illustrating a configuration of the transmission control apparatus 10 according to the present embodiment.

  The transmission control device 10 includes a verification unit 11 that acquires a mail condition indicated by a ticket attached to a received electronic mail, and determines that transmission is possible if the electronic mail satisfies the mail condition, and transmission is impossible if the electronic mail does not satisfy the mail condition. Further, the transmission control device 10. An e-mail determined by the verification unit 11 to be transmittable is transmitted to a destination address specified in the e-mail, and an e-mail determined to be unsendable is not transmitted to the destination address.

  The verification unit 11 and the transmission determination unit 12 are, for example, the verification unit 18 and the transmission determination unit 19, but may have other configurations that perform an equivalent function.

  The transmission control apparatus 10 according to the present embodiment can execute the transmission permission / inhibition determination based on various conditions while transmitting a mail while suppressing a delay caused by an administrator or the like. The reason is that the verification unit 11 acquires the mail condition indicated by the ticket attached to the mail, and determines that transmission is possible if the electronic mail satisfies the mail condition, and transmission is not possible if the electronic mail does not satisfy the mail condition. Tickets are issued prior to the transmission of e-mails and can contain various information. By giving this ticket to an email when sending an email, the user can send emails with various email conditions that are difficult to control with an inflexible email server filter by suppressing the delay caused by the administrator when sending email. . That is, the transmission control apparatus 10 according to the present embodiment can specify various different filter conditions for each user, and even for the same user even for each mail.

  The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Transmission control apparatus 11 Verification means 12 Transmission determination means 14 Ticket issuing part 16 Verification reception part 18 Verification part 19 Transmission determination part 20 Mail transmission / reception apparatus 21 Mail reception part 22 Mail transmission part 31 User terminal apparatus 32 Administrator terminal apparatus 60 Computer apparatus 61 processor 62 external storage device 63 main storage unit 64 bus 65 program

Claims (10)

A verification unit that acquires a mail condition indicated by a ticket attached to the received e-mail, and determines that transmission is possible if the e-mail satisfies the mail condition;
The e-mail that the verification means has determined to be able to send is sent to the destination address specified in the e-mail, and the e-mail that has been determined to be unsendable is not sent to the destination address. A transmission control device comprising: The email condition includes a maximum size of the attached file of the email,
The transmission control apparatus according to claim 1, wherein the verification unit determines whether or not the electronic mail satisfies the mail condition by comparing a size of the attached file of the electronic mail with the maximum size. The email condition includes a designated type that is a type of file that may be attached to or prohibited from the email,
The transmission control apparatus according to claim 1, wherein the verification unit compares the type of the attached file of the electronic mail with the specified type to determine whether the electronic mail satisfies the mail condition. The e-mail condition includes designation of a domain in which transmission is permitted or prohibited.
The verification unit compares the domain included in the transmission destination address with the domain where transmission is permitted or prohibited, and determines whether the email satisfies the mail condition. The transmission control device according to claim 1.   The transmission according to claim 1, wherein the verification unit determines that the e-mail cannot be transmitted unless the address indicated by the ticket attached to the input e-mail matches the transmission source address of the e-mail. Control device. A ticket issuance application mail is received from the user terminal device and transferred to the administrator terminal device, a ticket issuance response mail specifying the mail condition is received from the administrator terminal device, and the mail conditions and the user terminal are received. Ticket issuing means for generating the ticket, which is a file in which the address of the device is described, and encrypting and transmitting to the user terminal device;
The transmission control apparatus according to claim 5, further comprising: a verification receiving unit that receives the electronic mail to which the ticket is attached, extracts the ticket, decrypts the ticket, and outputs the decrypted ticket to the verification unit. Obtain the mail condition indicated by the ticket attached to the received e-mail, determine that transmission is possible if the e-mail satisfies the e-mail condition, and determine that transmission is not possible otherwise,
A transmission control method for transmitting the e-mail determined to be transmittable to a destination address specified in the e-mail and not transmitting the e-mail determined to be unsendable to the destination address. The email condition includes a maximum size of the attached file of the email,
The transmission control method according to claim 7, wherein the size of the attached file of the electronic mail is compared with the maximum size to determine whether the electronic mail satisfies the mail condition. Obtain the mail condition indicated by the ticket attached to the received e-mail, determine that transmission is possible if the e-mail satisfies the e-mail condition, and determine that transmission is not possible otherwise,
A transmission control program for causing the computer to execute processing for transmitting the e-mail determined to be transmittable to a destination address specified in the e-mail and not transmitting the e-mail determined to be unsendable to the destination address . The email condition includes a maximum size of the attached file of the email,
The transmission control program according to claim 9, wherein the computer executes a process of determining whether or not the electronic mail satisfies the mail condition by comparing the size of the attached file of the electronic mail with the maximum size.

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