JP2013038473A - Server device and mail relay program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a load on a server device for relaying mails, and also to effectively use a network resource.SOLUTION: A server device is used for relaying an e-mail. The server device includes: a communication control part 4 for exchanging a pre-mail with an upstream side relay source server device (another server device 3) connected to a network, which includes mail identification information for specifying the content of a mail text and confirming the transmission necessity of the mail text; a storage part 6 for storing the mail text or the mail identification information; and a control part 8 for determining the transmission necessity of the mail text on the basis of the mail identification information and outputting a response indication with respect to the transmission necessity of the mail text to the relay source server device.

Description

The present invention relates to a server device that relays electronic mail, for example, a server device that relays mail to a destination registered in a mailing list, and a mail relay program.

  Some server devices that relay electronic mail have a mailing list function in which address information of a plurality of destinations is registered in advance. Then, the sender of the e-mail can send e-mails having the same contents to a plurality of opponents registered in the mailing list by designating the mailing list address and sending the e-mail.

  With regard to such a mailing list function, Patent Document 1 describes that a server device that stores a mailing list returns mailing list information to a client device, and a user selects a destination from the mailing list information to send an email. Yes.

Also, in Patent Document 2, if the received mail is the same sender as the mail that has already been received, it is checked whether the mail text matches, and if it matches, it is newly acquired. It is described that the mail is discarded.

JP 2001-156829 A JP 2000-1112843 A

  By the way, one e-mail address may be registered in a plurality of mailing lists. In this case, for the mailing list address designated by the mail sender, the recipient receives the same mail relayed by different routes a plurality of times by the mail address registered in each server device that relays the mail. There's a problem.

  FIG. 47 is referred to when mail is sent using the mailing list. FIG. 47 shows a configuration example of a mail relay system that transfers a plurality of the same mails via a multi-stage mailing list. The mail relay system 1000 includes, for example, a transmission-side server device S, reception-side server devices P1 and P2, and relay server devices M1, M2, and M3. For example, the sender transmits a mail 1002 specifying “x @ P1” as destination information, a mail 1004 specifying “m1 @ M1”, and a mail 1006 specifying “m3 @ M3”.

  Here, the destination information “x @ P1” specified in the mail 1002 indicates, for example, that the mail is transmitted to the transmission destination “x” via the reception server “P1”. Further, the destination information “m1 @ M1” of the mail 1004 indicates that the mailing list “m1-list” of the relay server “M1” is designated and transmitted. Similarly, the destination information “m3 @ M3” of the mail 1006 indicates that the mailing list “m3-list” of the relay server “M3” is designated and transmitted.

  When the mails 1002, 1004, and 1006 specifying the destination information are transmitted in this way, the mail 1002 specifying the receiving side “x” is directly transmitted to the receiving server P1. Mails 1004 and 1006 specifying the mailing list are transmitted to the specified relay server apparatuses M1 and M3. The server apparatus M1 that has received the mail 1004 reads the designated mailing list “m1-list”. Then, using the destination address registered in the mailing list as destination information, for example, a mail 1008 specifying “m2 @ M2” and a mail 1010 specifying “y @ P1” are created and transmitted. Similarly, the server apparatus M3 that has received the mail 1006 reads the designated mailing list “m3-list”. The destination address registered in the mailing list is used as destination information. For example, a mail 1012 designating “x @ P1”, a mail 1014 designating “y @ P1”, and a mail 1016 designating “z @ P2”. Create and send.

  In addition, the server apparatus M2 that has received the mail 1008 reads, for example, the designated mailing list “m2-list”, and creates and transmits the mail 1018 designating the registered address “x @ P1”.

  Thereby, for example, the mail 1002, 1012, 1018 is transmitted to the transmission destination “x” and the mails 1010, 1014 are transmitted to the transmission destination “y” to the server device P1 on the receiving side. . That is, when a plurality of server devices storing mailing lists are designated and mail transmission is performed, the server device P1 on the receiving side receives the same content mail a plurality of times.

  Transferring the same mail to all the relaying servers in this way occupies network resources, and further, the load on the receiving server that receives many of the same mails is excessive. Further, the receiving server device receives a large number of identical mails, and storing all of them requires a huge storage area.

Therefore, in view of the above problems, the purpose of the server device and the mail relay program of the present disclosure is to reduce the load on the server device that relays mail and to effectively use network resources.

In order to achieve the above object, the server device or mail relay program of the present disclosure is used for relaying electronic mail. A pre-mail that includes mail identification information that identifies the contents of the mail text and confirms whether the mail text needs to be transmitted is transmitted / received to / from the upstream relay source server device connected to the network. The mail text or the mail identification information is stored in a storage unit. Then, it is determined whether or not transmission of the mail text is necessary from the mail identification information, and a response instruction indicating whether or not transmission of the mail text is necessary is output to the relay source server device.

  According to the server device or the mail relay program of the present disclosure, any of the following effects can be obtained.

  (1) A pre-mail is sent before the mail text is sent, and the upstream server device is notified of the necessity of sending the mail text determined based on the mail identification information contained in the pre-mail. It is possible to prevent the contents of the mail body from being received multiple times.

  (2) By sending / receiving pre-mails with a small amount of data and confirming whether or not the mail text needs to be sent, the mail text is not duplicated in the server device that relays the mail, and forwarding processing is not performed. Therefore, it is possible to reduce network resource occupancy and server device capacity load.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is a figure which shows the structural example of the server apparatus which concerns on 1st Embodiment. It is a figure which shows the structural example of a mail relay system. It is a figure which shows the structural example of a mail and a pre mail. It is a figure which shows the structural example of a transmission destination list. It is a flowchart which shows an example of the mail relay process of a server apparatus. It is a flowchart which shows an example of the mail relay process of a server apparatus. It is a figure which shows the function structural example of the mail relay server apparatus which concerns on 2nd Embodiment. It is a figure which shows the structural example of a server apparatus. It is a figure which shows an example of a transmission mail. It is a figure which shows an example of a premail. It is a figure which shows an example of the transmission response of a premail. It is a figure which shows the structural example of a mail relay system. It is a figure which shows the structural example of a transmission destination management table. It is a figure which shows the sequence of the example of a mail relay process. It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (S). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (S). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (M1). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (M2). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (P1). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (M3). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (P2). It is a flowchart which shows an example of the process by mail reception. It is a flowchart which shows an example of the destination information extraction process in a transmission destination list | wrist. It is a flowchart which shows an example of the destination information extraction process in a transmission destination list | wrist. It is a flowchart which shows an example of the process by pre-mail (Pre-mail) reception. It is a flowchart which shows an example of the destination information extraction process in a transmission destination list | wrist. It is a flowchart which shows an example of the process by the response (Pre-ACK) reception of a premail. It is a flowchart which shows an example of the process by the response (Pre-ACK) reception of a premail. It is a figure which shows the structural example of the mail relay system which concerns on 3rd Embodiment. It is a sequence diagram which shows an example of a mail relay process. It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (M3). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (M3). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (M4). It is a figure which shows an example of the production | generation or update state of the transmission destination management table in a server apparatus (P2). It is a flowchart which shows an example of the process by the mail reception which concerns on 4th Embodiment. It is a flowchart which shows an example of the process by the mail reception which concerns on 4th Embodiment. It is a flowchart which shows an example of the process by the response (Pre-ACK) reception of a premail. It is a flowchart which shows an example of the process by the response (Pre-ACK) reception of a premail. It is a figure which shows the structural example of the transmission destination management table which concerns on 5th Embodiment. It is a flowchart which shows an example of the destination information extraction process in a transmission destination list | wrist. It is a flowchart which shows an example of the process by pre-mail (Pre-mail) reception. It is a flowchart which shows an example of the destination information extraction process in a transmission destination list | wrist. It is a flowchart which shows an example of the process by the mail reception which concerns on 6th Embodiment. It is a flowchart which shows an example of the process by the mail reception which concerns on 6th Embodiment. It is a flowchart which shows an example of the process by the response (Pre-ACK) reception of a premail. It is a flowchart which shows an example of the process by the response (Pre-ACK) reception of a premail. It is a figure which shows the example of a state which receives two or more same mails.

[First Embodiment]

  The first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration example of a server apparatus according to the first embodiment. The configuration illustrated in FIG. 1 is an example, and the present invention is not limited to such a configuration.

  This server device 2 is an example of the server device of the present disclosure, and is a means for relaying transmission / reception of electronic mails with other connected server devices 3. The server device 2 is means for sending and receiving mail to and from an electronic device such as a connected PC. In the e-mail relay process, the server device 2 transmits / receives a pre-mail that does not include the mail text to / from another server apparatus 3 that relays the mail before the mail text is transmitted. ing. In the transmission / reception of the pre-mail, the server 2 and the other server 3 notify the mail transmission destination information and, for example, whether the other server 3 of the communication destination requests the transmission of the mail text. Confirm that. The server device 2 includes, for example, a communication control unit 4, a storage unit 6, and a control unit 8.

  The communication control unit 4 is an example of means for transmitting and receiving mail and the above-described pre-mail with other server devices 3 and electronic devices connected on the network. For example, when the server device 2 is on the downstream side in the mail relay route, the communication control unit 4 is connected to the relay source server device that is the other server device 3 on the upstream side connected on the network. Send and receive pre-mails. Further, when the server device 2 is on the upstream side in the mail relay route, the communication control unit 4 performs, for example, a relay destination server device that is another server device 3 on the downstream side registered in the transmission destination list. Send a pre-mail.

  This pre-mail includes, for example, transmission destination information such as a mail address, mail identification information for specifying the contents of the mail text, and confirmation of the necessity of transmission of the mail text.

  The storage unit 6 is an example of a unit that stores a mail text and mail identification information. In addition, the storage unit 6 stores a destination list that manages whether or not the mail text needs to be transmitted, such as destination information set in an email or a pre-mail or destination information registered in a mailing list. .

The control unit 8 is an example of a unit that determines whether the transmission of the mail text is necessary and manages transmission of the mail text to the transmission destination of the mail or the pre-mail. If the server device 2 is on the downstream side of the mail relay route, it is determined whether or not the mail text needs to be transmitted from the mail identification information included in the received pre-mail, and whether or not the mail text is necessary for the relay server apparatus. The response instruction is sent. If the server apparatus 2 is upstream of the mail relay path, the transmission destination list is updated in response to a transmission necessity response from the relay destination server apparatus, and the mail text is sent to the relay destination server apparatus that has received the transmission request. To send.

  Next, the configuration of the mail relay system using this server device will be described with reference to FIGS. 2 is a diagram illustrating a configuration example of a mail relay system, FIG. 3 is a diagram illustrating a configuration example of a mail and a pre-mail, and FIG. 3 is a diagram illustrating a configuration example of a transmission destination list. The configurations shown in FIGS. 2 to 4 are examples, and the present invention is not limited to such configurations.

  In the mail relay system 10 shown in FIG. 2, a plurality of server devices 2 are connected on a network. The mail relay system 10 transmits mail from a mail transmission source a to transmission destinations x, y, and z, and includes server devices 20, 22, and 24, for example. These server devices 20, 22, and 24 are the server device 2 in FIG. 1 and constitute another server device 3 as a relay destination. In this mail relay system 10, for example, PCs (Personal computer) 12, 14, 16, and 18 are connected as electronic devices of a mail transmission source a and electronic devices of a transmission destination.

  The PCs 12, 14, 16, and 18 are examples of electronic devices having e-mail creation and transmission / reception functions. For example, input means for inputting characters and numbers, display means for displaying e-mails, and e-mail transmission / reception. The communication means to perform is provided. Here, the PC 12 is an example of an electronic device that creates a mail 26 and transmits the mail 26 using the mail relay system 10 on the e-mail sender a side, for example. The PC 12 is connected to the server device 20 constituting the mail relay system 10 based on, for example, setting of a communication destination and physical distance information, and the created mail 26 is transmitted to the server device 20. The PCs 14, 16, and 18 are examples of electronic devices that perform e-mail reception processing and display processing for x, y, and z on the mail receiving side.

  Note that the electronic devices of the transmission source a and the transmission destinations x, y, and z are not limited to PCs. For example, a mobile phone or a personal digital assistant (PDA) may be used.

  The server device 20 constitutes a transmission server device connected to the sender-side PC 12, for example, a transmission server (S) that directly receives the mail 26 transmitted from the PC 12 and sends it to the mail relay system 10. doing. Then, the server device 20 performs mail transfer processing by sending / receiving pre-mails to / from other relay server devices 22 and 24 based on the destination information set in the mail 26, transmission management of the mail text, and the like.

  The server device 22 is connected to the PCs 14, 16, and 18 on the receiving side and constitutes a receiving server (P) that transmits the mail text to the PC set in the transmission destination information of the mail 26. Further, in the server device 22, in the mail relay process, a response process is performed with respect to the necessity of transmission of the mail text included in the transmitted pre-mail.

  The server device 24 is an example of means for transmitting mail between the server devices 20 and 22 in a different route in the mail relay system 10, and constitutes a relay server (M). The server device 24 stores, for example, a mailing list 28 in which one or a plurality of mail transmission destination information is registered in advance. Therefore, the sender “a” can send the mail 26 to the registered destinations by designating this mailing list 28, without having to set input of all the destinations as the destinations of the mails 26. .

  In the mail relay system 10, a pre-mail is transmitted / received between a server apparatus on the upstream side and a server apparatus on the downstream side of a mail relay path before a mail text is transmitted / received. This mail relay route is determined by, for example, the transmission destination address specified in the transmission mail, server device information, and the like. In the transmission mail 26 shown in FIG. 2, for example, a transmission destination indicating the transmission server S to the reception server P and a transmission destination designated from the transmission server S to the mailing list 28 of the relay server M are set. In the mailing list 28, for example, a transmission destination indicating the receiving server P is set. By this transmission destination information, the mail relay route is changed from the server device (S) 20 to the server device (P) 22, the server device (S) 20 to the server device (M) 24, and the server device (M) 24 to the server device (P). 22 is set.

  When the mail 26 is transmitted from the sender a, for example, the transmission server device (S) 20 at the most upstream of the mail relay path sends the pre-mail 30 and the server device (M) to the server device (P) 22 on the downstream side. ) A pre-mail 31 is transmitted to 24. The server device (M) 24 that has received the pre-mail 31 transmits a pre-mail 32 to the downstream server device (P) 22.

  The pre-mails 30, 31, and 32 are examples of confirmation means for determining whether it is necessary to transmit an e-mail text to each server device. For example, the pre-mails 30, 31, and 32 are different from those shown in FIG. As shown in FIG. 4, the header part 34 is formed by excluding the mail body 33. The pre-mails 30, 31, and 32 include, for example, a message ID (Message-ID) 35 that is identification information for uniquely identifying the contents of the mail text 33, together with the sender information and destination information of the transmission mail 26. It is included.

  The server devices 22 and 24 that have received the pre-mails 30 and 31 transmit, for example, a reply notification (Pre-ACK) indicating whether or not the mail text 33 is necessary for transmission to the server device 20 on the sender side of the pre-mail. Similarly, the server device 22 also transmits a reply notification indicating whether transmission is necessary to the server device 24. Regarding the necessity of transmission of the mail text, for example, each server device 22, 24 has already received the same mail text 33 and stored it in the storage unit 6 or the like, or with other server devices 3 It is determined whether or not it is determined that the same mail text 33 is transmitted between them. When the mail text 33 has already been stored or when it has been decided to receive the mail text 33 from another server device, the server device that has received the pre-mail is the server device that has transmitted the pre-mail. In response to this, a reply notification indicating that transmission of the mail body 33 is unnecessary is transmitted.

  When the upstream server apparatus 20 receives the reply notification indicating whether transmission is necessary, the upstream server apparatus 20 transmits the mail text 33 according to the reply result. Further, in the server device (M) 24 that is not the receiving server, the upstream server device (S) 20 storing the mail text 33 is sent to the upstream server device (S) 20 according to the transmission necessity result from the downstream server device (P) 22. In response, a reply notification indicating whether transmission is necessary is transmitted.

  In order to manage the necessity of transmission of the mail text, for example, each of the server devices 20, 22, and 24 creates a transmission destination list 36 shown in FIG. The transmission destination list 36 is an example of a mail relay management unit, and includes, for example, a transmission destination information area 37, a server information area 38, and a transmission necessity information area 39.

  The transmission destination information area 37 stores, for example, the transmission destination information set in the transmission mail 26, the transmission destination information of the pre-mail, or the transmission destination information registered in the mailing list, and manages the transmission destination of the mail.

  In the server information area 38, for example, a destination device described in the destination information area 37, a mailing list, or the like is stored, or information for specifying a connected server device is stored.

  The transmission necessity information area 39 manages, for example, the result of reply notification to the pre-mail transmitted to the transmission destination server device in the transmission destination information area 37. That is, a reply indicating whether or not the mail text needs to be transmitted is registered, for example, “required” is indicated when a transmission request for the mail text 33 is indicated, “no” is required when transmission is not required, and “undecided” is awaited for a reply. And manage it.

  In the mail relay system 10 shown in FIG. 2, for example, “x @ P” and “m @ M” are designated as destination information of the transmission mail 26. In addition, for example, “x @ P”, “y @ P”, and “z @ P” are registered in the mailing list (m) 28, and are specified as mail transmission destinations. For example, the server device (P) 22 reads the destination information “x @ P” from the pre-mail 30 received from the server device (S) 20, and the destination from the pre-mail 32 received from the server device (M) 24. Information “x @ P”, “y @ P”, and “z @ P” are read out.

  For example, when the server apparatus (P) 22 receives the mail text 33 from the server apparatus (S) 20 or decides to receive the mail body 33, the server apparatus (P) 22 notifies the server apparatus (S) 20 of a reply “required” for transmission. The server device (M) 24 is notified of the transmission “No” reply. Then, the server device (P) 22 relays the mail in which the destination information “x @ P” is designated to the PC 14 on the receiving side “x”. Further, the server device (S) 22 transmits the mail text 33 transmitted from the server device (P) 20 to the transmission destination read by the pre-mail 32. In this case, the server apparatus (P) 22 transmits the same content of the transmission destination information registered in the mailing list (m) 28 to the destination information “x @ P” of the transmission destination that is scheduled to be transmitted. Does not send duplicate emails. This determination of duplication of mail transmission destinations may be managed using, for example, the transmission destination list 36 stored in the server device (P) 22.

  Next, the mail relay process will be described with reference to FIGS. 5 and 6 are flowcharts showing an example of mail relay processing of the server device. The processing content, processing order, and the like shown in FIGS. 5 and 6 are examples, and the present invention is not limited to such a configuration.

  The mail relay process of this server device is an example of the mail relay program of the present disclosure, and includes a process for confirming whether or not the mail text needs to be transmitted by sending / receiving a pre-mail prior to the mail text transmission process. The process shown in FIG. 5 is an example of the process of the server device arranged on the downstream side of the mail relay route, for example, and the process shown in FIG. 6 is the example of the server device arranged on the upstream side of the mail relay route, for example. It is an example of a process.

  As shown in FIG. 5, when the server device receives the pre-mail from the upstream server device on the mail relay path (S1), the server device extracts the message ID as the mail identification information from the pre-mail (S2). Also, destination information for mail transmission is extracted from the pre-mail (S3). The downstream server device acquires the transmission of the mail by receiving the pre-mail, the transmission destination or the relay destination information, and grasps the content of the transmitted mail text.

  Then, the server device determines whether the same mail text is already stored from the acquired mail identification information or whether the same mail text is determined to be transmitted (S4). That is, if the same email text has already been sent, the email text will not be sent again. Similarly, when the same mail text is determined to be transmitted to another server device, the same mail text is prevented from being duplicately transmitted.

  For example, when a mail text having the same mail identification information is stored or is scheduled to be transmitted (YES in S4), a response indicating whether transmission is necessary or not is transmitted to the server apparatus that is the transmission source of the pre-mail ( S5). Then, the server device transmits the mail text to the destination information of the pre-mail using the stored mail text or the mail text received from another server device (S6).

  In addition, when the mail text that matches the mail identification information of the pre-mail is not stored, or when the mail text is not scheduled to be sent (NO in S4), a response requesting the mail text is sent to the pre-mail sender. Transmit (S7). Then, after receiving the mail text from the upstream server device (S8), the mail text is transmitted to the destination indicated in the pre-mail (S6).

  Further, as shown in FIG. 6, the upstream server apparatus generates or updates the transmission destination list by starting mail transmission processing or relay processing, for example (S <b> 21). This transmission destination list is generated using, for example, transmission destination information of received mail or pre-mail, or transmission destination information registered in a mailing list stored in the server device.

  In accordance with the destination list, the server device transmits a pre-mail to the downstream server device for confirming whether or not it is necessary to send a mail transmission notification or a mail text (S22). When a response to the transmitted pre-mail is received (S23), information such as the necessity of transmission of the mail text included in the response is registered and the transmission destination list is updated (S24).

  Referring to the destination list, it is determined whether there is a server device that requests transmission of the mail text (S25), and the mail text is transmitted in response to the transmission request (YES in S25) (S26).

  According to such a configuration, the upstream server apparatus is notified of the necessity of transmission of the mail text by the mail identification information included in the pre-mail received before the mail text is transmitted. Thereby, for example, it is possible to prevent a mail having the same content from being relayed between different server apparatuses for the same transmission destination information registered in a plurality of mailing lists or the like. The recipient can prevent receiving the same text content multiple times. By sending / receiving pre-mails with a small data capacity and confirming the necessity of sending the mail text, the mail text is duplicated and stored in the server device that relays the mail, or the forwarding process is not performed. Resource occupancy and server device capacity load can be reduced.

  [Second Embodiment]

  Next, a second embodiment will be described with reference to FIGS. 7, 8, 9, 10, and 11. 7 and 8 are diagrams illustrating an example functional configuration of the mail relay server device according to the second embodiment, and FIG. 8 is a diagram illustrating a configuration example of the server device. FIG. 9 is a diagram illustrating an example of a transmitted mail, FIG. 10 is a diagram illustrating an example of a pre-mail, and FIG. 11 is a diagram illustrating an example of a pre-mail transmission response. The configurations shown in FIGS. 7 to 11 are examples, and the present invention is not limited to such configurations.

  This server device 40 is an example of the server device of the present disclosure, and is connected to other server devices by wireless or wired to perform mail relay processing. Before sending, send / receive pre-mail to / from other server devices. The server device 40 includes, for example, a pre-mail receiving unit 42, a mail receiving unit 44, a pre-mail transmitting unit 46, a mail transmitting unit 48, a mailing list folder 50, a transmission destination management folder 54, a relay folder 58, and the like.

  The pre-mail receiving unit 42 receives a pre-mail (Pre-mail) transmitted from a server device on the upstream side of the mail relay route, or a response (Pre (-mail) to a pre-mail transmitted from the downstream server device. -ACK) is an example of a communication means for receiving, for example, the communication control unit 4. When receiving the pre-mail, the pre-mail receiving unit 42 refers to the mailing list 52 stored in the mailing list folder 50, for example. Then, the destination information registered in the mailing list 52 and the destination information specified in the pre-mail are notified to the destination management folder 54, and, for example, the transmission management table 56 is generated and the destination information is added.

  In addition, when the pre-mail receiving unit 42 receives a mail text in response to the pre-mail, the pre-mail receiving unit 42 instructs the mail receiving unit 44, for example, a mail storage destination as a mail reception preparation instruction.

  The mail receiving unit 44 is means for receiving a mail (e-mail) 60 transmitted from the upstream server device on the mail relay path, and is configured by the communication control unit 4 described above. For example, the mail reception unit 44 issues a reception notification to the storage location instruction from the pre-mail reception unit 42. When the mail 60 is received, for example, the mail text 78 in the mail 60 is stored in the relay folder 58. When this server device 40 is connected to the sending PC, it becomes the most upstream server device in the mail relay path, and the downstream server device sends the mail text received from the sending PC. Send.

  The pre-mail transmission unit 46 transmits a pre-mail to the downstream server device on the mail relay path, and also responds to the upstream server device whether the mail text is necessary (Pre (-mail) -ACK). This is an example of the communication means for notifying the above-mentioned communication, and includes the communication control unit 4 described above. The pre-mail transmission unit 46 transmits the necessity of transmission of the mail text, the identification information of the mail text, etc. to the mailing list 52 and the destination information set in the received pre-mail or mail 60. Then, when a response to the pre-mail is received from the communication destination server device, the response contents and the like are notified to the transmission destination management table 56 of the transmission destination management folder 54 so that the transmission destination management table 56 is changed or updated. . Then, the pre-mail transmission unit 46 notifies the mail transmission unit 48 of the relay instruction when relaying the mail text based on a response from another server device, for example.

  In addition, the pre-mail transmission unit 46 performs, for example, a synchronization process for controlling the processing order of transmission / reception of the pre-mail and the mail text 60 with the pre-mail reception unit 42.

  The mail transmission unit 48 is an example of a unit that transmits the mail 60 to the downstream server device, and includes the communication control unit 4 described above. In addition, when the transmission destination information set in the mail 60 is the server itself, the mail transmission unit 48 stores the mail text 78 in the personal mail box 62 corresponding to the transmission destination information.

  Here, the mail 60 transmitted / received by the server device 40 is composed of, for example, a mail header 76 and a mail text 78 as shown in FIG. As described above, the mail header 76 includes a message ID that is identification information of the mail text together with the sender and destination of the mail. As shown in FIG. 10, the pre-mail 80 includes, for example, a sender, a destination, and a message ID in the mail header 76. In this case, for example, a pre-mail 80 is generated for each transmission destination set in the mail 60.

  Further, in response to the transmitted pre-mail 80, the transmission response (Pre-mail-ACK) 82 received from the downstream server device includes, for example, as shown in FIG. No 81 is added. Thereby, in the server apparatus 40, the transmission destination management table 56 is updated about the subject mail text and the necessity of the transmission response. Further, the server device 40 further responds to the upstream side server device on the necessity of transmission of the mail text based on the response result of the transmitted pre-mail 80.

  The mailing list folder 50 is a means for storing a mailing list 52 in which mail destination information is registered, and is composed of the storage unit 6 described above.

  The transmission destination management folder 54 is a means for performing transmission / reception management of the mail body for each piece of identification information indicating the content of the mail body 78, for example, regarding the transmission destination information specified in the pre-mail and the transmission destination information registered in the mailing list 52. It is an example. In this transmission destination management folder 54, for example, a transmission destination management table 56 is set. The transmission destination management table 56 is set according to the transmission / reception result of the pre-mail or the result of necessity of transmission of the mail text from the downstream server device. Perform update processing.

  The relay folder 58 is a means for storing the received mail text 60, and is connected to the mail receiving unit 44 and the mail transmitting unit 48.

  For example, as shown in FIG. 8, the server device 40 includes a CPU (Central Processing Unit) 63, a communication control unit 64, and a storage unit 66. The CPU 63 is a means for performing arithmetic processing such as an OS (Operating System) for operating the server device 40, a mail relay program for transmitting and receiving a pre-mail and a mail text, a transmission destination management program, and the like. Configure. The storage unit 66 stores, for example, the control program described above, a ROM (Read Only Memory) 70 that stores the mailing list 52, the transmission destination management folder 54, the received mail text 60, and the like, and a RAM that constitutes a work area of the program. (Random Access Memory) 72 and the like.

  The communication control unit 64 is an example of a unit that controls connection of the server device 40 to the network 68. The network 68 to which the server device 40 is connected and relays mail may be, for example, an internal LAN or an intranet in addition to external communication such as the Internet.

  The above-mentioned mail relay program, transmission destination management program, and transmission destination information such as a mailing list are not limited to those stored in the ROM 70, and can be read by a computer such as a magnetic disk, flexible disk, optical disk magneto-optical disk, etc. What is stored in a simple recording medium may be used. Furthermore, a program or the like may be read from a server or database on the network and used.

  Next, the configuration of the mail relay system and transmission destination management will be described with reference to FIGS. FIG. 12 is a diagram illustrating a configuration example of the mail relay system, and FIG. 13 is a diagram illustrating a configuration example of the transmission destination management table. The configurations shown in FIGS. 12 and 13 are examples, and the present invention is not limited to such configurations.

  The mail relay system 90 shown in FIG. 12 includes a transmission-side server device (S) between the electronic device “a” on the mail transmission side and the electronic devices “x”, “y”, and “z” on the mail reception side. Side server devices (P1) and (P2) and relay server devices (M1), (M2) and (M3) are arranged. The relay server device (M1) includes, for example, a mailing list (m1-list) 92, the relay server (M2) includes a mailing list (m2-list) 94, and the relay server (M3) includes a mailing list (m3-list). 96 is stored.

  In such a configuration, the electronic device “a” side creates and transmits a mail 60 specifying, for example, destinations “x @ P1”, “m1 @ M1”, and “m3 @ M3” as transmission destinations. Yes. The transmission-side server device (S) that has received the mail 60 transmits, for example, a pre-mail that confirms whether or not the mail text needs to be transmitted toward the downstream side of the mail relay path according to the destination information. As described above, this pre-mail includes, for example, “123456.a” as a message ID for identifying the mail text. The server apparatus (S) transmits a pre-mail (1) 98 to the server apparatus (P1), transmits a pre-mail (2) 100 to the server apparatus (M1), and transmits to the server apparatus (M3). The pre-mail (3) 102 is transmitted.

  The server device (M1) reads the stored mailing list 92 according to the destination of the received pre-mail (2) 100, and includes the message ID of the mail text for the destination registered in the mailing list 92. send an email. That is, the server apparatus (M1) designates the mailing list (m2-list) 94, designates the pre-mail (4) 104 directed to the server apparatus (M2) and the transmission destination “y”, and designates the server apparatus (P1). A pre-mail (5) 106 directed to is transmitted.

  The server apparatus (M2) receives the pre-mail (4) 104, specifies the destination “x” in accordance with the designated mailing list (m2-list) 94, and sends the pre-mail (6) to the server apparatus (P1). ) 108 is transmitted.

  Similarly, the server apparatus (M3) designates the destinations “x” and “y” in accordance with the mailing list (m3-list) 96 designated by the pre-mail (3) 102, and sends it to the server apparatus (P1). Designated pre-mail (7) 110 and transmission destination “z” are designated and pre-mail (8) 112 directed to the server apparatus (P2) is transmitted.

  Each server device (S), (P1), (P2), (M1), (M2), (M3) constituting the mail relay system 90 is, for example, as shown in FIG. The transmission destination management table 120 for managing the identification information and the transmission destination is registered. The transmission destination management table 120 includes, for example, a message ID area 122 for identifying a mail text to be transmitted, a pre-mail reception source area 124, a reception necessity area 126, and a transmission destination list area 128. The reception source area 124 is an area for specifying an upstream server device that transmits the mail text. For example, in the case of the transmission server (S), “most upstream” is registered.

  The reception necessity area 126 is an area for registering whether or not the mail text needs to be transmitted for the server apparatus storing the transmission destination management table 120. The necessity result is sent to the upstream server apparatus. Send as pre-mail response. Whether or not the mail text needs to be transmitted may be determined based on, for example, a response from the downstream server device to which the server device has transmitted the pre-mail.

  The transmission destination list area 128 registers transmission destination information of pre-mails. For example, transmission destination information specified in the mail 60 and transmission destination information registered in a mailing list stored in each server device are described. In this transmission destination list, for example, the transmission destination, the server name, and the necessity of transmission as a result of the pre-mail response from the transmission destination are described.

  Next, examples of relay processing of pre-mail and mail text by the mail relay system will be described with reference to FIGS. 14, 15, 16, 17, 17, 18, 20, and 21. FIG. FIG. 14 is a diagram illustrating a sequence of the mail relay processing example, and FIGS. 15 to 21 illustrate an example of a generation or update state of the transmission destination management table in each server device. The configurations and processing procedures or processing contents shown in FIGS. 14 to 21 are examples, and the present invention is not limited to such configurations.

  As shown in FIG. 14, when the electronic device “a” on the transmission side transmits the mail 60 (S31), the server apparatus (S) receives the mail 60 and extracts the message ID 35 of the mail 60. Then, the server apparatus (S) refers to the transmission destination management folder 54 and confirms that there is no instance of the transmission destination management table 120 corresponding to this message ID. This instance indicates, for example, already generated processing data of the transmission management table 120. In this processing, it is determined whether or not there is a transmission management table 120 corresponding to the same message ID before. That is, when the server apparatus (S) receives the mail 60 indicated by this message ID for the first time, the instance of the transmission destination management table 120 is not held.

  Therefore, the server apparatus (S) generates an instance of the transmission destination management table for the message ID of the received mail 60 in the transmission destination management folder 54. In this transmission destination management table, for example, as shown in FIG. 15A, a transmission destination management table 130 in which the transmission destination list 133 is registered based on the transmission destination information of the received mail 60 is generated. Since this transmission destination management table 130 is held by the transmission server (S), “most upstream” is recorded in the reception source area 131, and no data in the reception necessity area 132.

  The pre-mail (1) (Pre-mail # 1) of the transmission destination “x @ P1” is transmitted to the transmission destination server (P1) (S32). The pre-mail (2) (Pre-mail # 2) of the transmission destination “m1 @ M1” is transmitted to the server apparatus (M1) (S33), and the transmission destination “m3 @” is transmitted to the server apparatus (M3). The pre-mail (3) (Pre-mail # 3) of “M3” is transmitted (S34).

  When the server apparatus (P1) receives the pre-mail (1) from the server (S), the server apparatus (P1) extracts the message ID and confirms whether or not an instance of the transmission destination management table corresponding to the message ID is held. Since the server apparatus (P1) has received this message ID for the first time, an instance of the transmission destination management table 160 is generated as shown in FIG. 19A. In the transmission destination management table 160, the reception source area 161 is the server device (S), and the transmission destination information 164 described in the pre-mail (1) is registered in the transmission destination list 163. In the transmission destination information 164, for example, the transmission destination x is set. Since the transmission destination x is connected to the server apparatus (P1), a “termination” indicating that it is connected to its own server is set in the mail transmission necessity area.

  Since the transmission destination “x @ P1” set in the pre-mail (1) is an electronic device connected to the server apparatus (P1), in order to transmit the mail 60 to this transmission destination “x”, The server device (P1) needs to receive the mail 60. Therefore, the server apparatus (P1) registers “required” in the reception necessity / non-necessity area 162, and transmits a transmission necessity / unnecessary “required” response ( Pre-ACK # 1) is transmitted (S35).

  When the server apparatus (S) receives the response from the server apparatus (P1), the server apparatus (S) updates the necessity of transmission in the area 134 of the server (P1) in the transmission destination list 133 to “necessary” as shown in FIG. 15B. Then, the mail text 78 stored in the server device (S) is transmitted to the server device (P1) (S36).

  When the server apparatus (P1) receives the mail text 78, the server apparatus (P1) reads the transmission destination management table 160 in which the message ID of the mail text 78 matches. Then, the server apparatus (P1) posts the mail text 78 to the personal mailbox 62 for “x” in the transmission destination area 134 for which transmission necessity is determined in the transmission destination list 163.

  When the server device (M1) receives the pre-mail (2) from the server device (S) (S33), the server device (M1) extracts the message ID and holds an instance of the transmission destination management table corresponding to the message ID. Check if it exists. Since the server apparatus (M1) has received this message ID for the first time, an instance of the transmission destination management table 140 is generated as shown in FIG. 17A. The server apparatus (M1) registers the server apparatus (S) in the reception source area 141, and is registered in the mailing list (m1-list) in accordance with the transmission destination information described in the pre-mail (2) in the transmission destination list 143. The destination information 144, 146 is registered.

  The server apparatus (M1) transmits a pre-mail (4) (Pre-mail # 4) to the server apparatus (M2) regarding “m2 @ M2” of the transmission destination information 146 (S37). Similarly, pre-mail (5) (Pre-mail # 5) is transmitted to the server apparatus (P1) regarding “y @ P1” in the transmission destination information 144 (S38).

  When the server apparatus (P1) receives the pre-mail (5), it extracts the message ID and determines whether there is an instance of the transmission destination management table relating to this message ID. Since the server apparatus (P1) has an instance of the transmission destination management table and has already acquired the mail with the same message ID, the transmission necessity / unnecessity of the server apparatus (M1) is set to “No”. A response (Pre-ACK # 5) is returned (S39). Then, as shown in FIG. 19B, the server apparatus (S) is registered in the reception source area 161, and “necessary” is registered in the reception necessity area 162.

  When the server apparatus (M1) receives the response from the server apparatus (P1), the transmission necessity information is changed to “No” for the transmission destination information area 144 of the server apparatus (P1) in the transmission destination list 143 shown in FIG. 17B. To do.

  When the server apparatus (M2) receives the pre-mail (4) from the server apparatus (M1), the message ID is extracted, and it is confirmed whether or not an instance of the transmission destination management table corresponding to the message ID is held. Since the server apparatus (M2) has received this message ID for the first time, an instance of the transmission destination management table 150 is generated as shown in FIG. 18A. In the transmission destination management table 150, the reception source area 151 is the server device (M1), and the transmission destination list 153 is registered in the mailing list (m2-list) according to the transmission destination information described in the pre-mail (4). The transmission destination information 154 is registered. Then, with respect to “x @ P1” in the transmission destination information 154, a pre-mail (6) (Pre-mail # 6) is transmitted to the server apparatus (P1) (S40).

  When the server apparatus (P1) receives the pre-mail (6), the server apparatus (P1) extracts the message ID and determines whether there is an instance of the transmission destination management table relating to the message ID. As described above, since the server apparatus (P1) has already acquired the mail with the same message ID, a response (Pre-ACK) indicating that transmission is necessary or not is sent to the server apparatus (M2). # 6) is returned (S41). Then, as illustrated in FIG. 19C, the server apparatus (S) is registered in the reception source area 161 and “necessary” is registered in the reception necessity area 162.

  When the server apparatus (M2) receives the response from the server apparatus (P1), the server apparatus (M2) changes the necessity of transmission to “no” for the area 154 of the server apparatus (P1) in the transmission destination list 153. Then, the server apparatus (M2) sets “no” as the necessity of transmission for all the transmission destinations in the transmission destination list 153, and does not need to receive the mail text 78. Then, a response (Pre-ACK # 4) indicating whether transmission is necessary or not is returned to the server apparatus (M1) (S42).

  When the server apparatus (M1) receives the response from the server apparatus (M2), as shown in FIG. 17C, the server apparatus (M1) determines whether or not transmission is necessary for the transmission destination information area 146 of the server apparatus (M2) in the transmission destination list 143. Change to Then, the server apparatus (M1) changes the reception necessity area 142 to "No" for all the transmission destinations in the transmission destination list 143, so that the server apparatus (S) changes the reception necessity area 142 to "No". A response (Pre-ACK # 2) indicating whether transmission is necessary or not is sent back (S43).

  When the server apparatus (S) receives the response from the server apparatus (M1), as shown in FIG. 16C, the server apparatus (S) determines whether or not transmission is necessary for the transmission destination area 136 of the server apparatus (P1) in the transmission destination list 133. Change to

  When the server device (M3) receives the pre-mail (3) from the server device (S) (S34), the server device (M3) extracts the message ID and holds an instance of the transmission destination management table corresponding to this message ID. To check. Since the server apparatus (M3) has received this message ID for the first time, an instance of the transmission destination management table 170 is generated as shown in FIG. 20A. The server device (M3) registers the server device (S) in the reception source area 171 and is registered in the mailing list (m3-list) according to the transmission destination information described in the pre-mail (3) in the transmission destination list 173. The destination information 174, 176, 178 is registered.

  The server apparatus (M3) pre-mails (7) (Pre-mail # 7) to the server apparatus (P1) regarding “x @ P1” of the transmission destination information 174 and “y @ P1” of the transmission destination information 176. Is transmitted (S44). In addition, the server apparatus (M3) transmits a pre-mail (8) (Pre-mail # 8) regarding “z @ P2” of the transmission destination information 178 to the server apparatus (P2) (S45).

  When the server apparatus (P1) receives the pre-mail (7), the server apparatus (P1) extracts the message ID and determines whether or not there is an instance of the transmission destination management table related to the message ID. Since the server apparatus (P1) has already acquired the mail with the same message ID, the server apparatus (M3) returns a response (Pre-ACK # 7) indicating whether or not transmission is necessary to the server apparatus (M3). (S46). Then, as shown in FIG. 19D, the server apparatus (S) is maintained in the reception source area 161, and “necessary” is maintained in the reception necessity area 162.

  When the server apparatus (M3) receives the response from the server apparatus (P1), as shown in FIG. 20B, the server apparatus (M3) determines whether transmission is required for the transmission destination information areas 174 and 176 of the server apparatus (P1) in the transmission destination list 173. Change to "No".

  When the server apparatus (P2) receives the pre-mail (8) from the server apparatus (M3), the server apparatus (P2) extracts the message ID and determines whether or not the destination management table instance corresponding to the message ID is held. Check. Since the server apparatus (P2) has received this message ID for the first time, an instance of the transmission destination management table 180 is generated as shown in FIG. Then, in the transmission destination management table 180, the reception source area 181 is the server device (M3), and the transmission destination information 184 described in the pre-mail (8) is registered in the transmission destination list 183.

  Since the transmission destination “z @ P2” set in the pre-mail (8) is an electronic device connected to the server device (P2), the server device (P2) sets “required” in the reception necessity area 182. Registration is performed, and a transmission necessity / unnecessity “necessary” response (Pre-ACK # 8) is transmitted to the server apparatus (M3) that is the source of the pre-mail (8) (S47).

  When the server apparatus (M3) receives the response from the server apparatus (P2), as shown in FIG. 20C, the server apparatus (M3) determines whether transmission is required for the transmission destination information area 178 of the server apparatus (P2) in the transmission destination list 173. Change to Since the server apparatus (M3) needs to transmit the mail text 78 to the downstream server apparatus (P2), “necessary” is registered in the reception necessity area 172 of the transmission destination management table 170. Then, the server apparatus (M3) returns a response (Pre-ACK # 3) indicating whether transmission is necessary or not to the server apparatus (P1) (S48).

  When the server apparatus (S) receives the response from the server apparatus (M3), as shown in FIG. 16D, the server apparatus (S) updates the necessity of transmission in the area 138 of the server (M3) in the transmission destination list 133 to “necessary”. Then, the mail text 78 stored in the server device (S) is transmitted to the server device (M3) (S49).

  The server device (M3) transmits the mail text 78 received from the server device (S) to the server device P2 (S50).

  When the server apparatus (P2) receives the mail text 78, the server apparatus (P2) reads the transmission destination management table 180 having the same message ID as shown in FIG. Then, the server device (P2) posts the mail text 78 to the personal mailbox 62 for “z” in the transmission destination information area 184 that is determined to be necessary in the transmission destination list 183.

  Next, FIG. 22, FIG. 23, FIG. 24, FIG. 25, FIG. 26 show the processing contents when receiving the mail text, the processing when receiving the pre-mail, and the processing contents when receiving the response to the pre-mail in each server device. 27 and 28 are referred to. The processing shown in FIGS. 22 to 24 shows processing examples of the server device that has received the mail, FIGS. 25 and 26 show processing examples of the server device that has received the pre-mail, and FIGS. The example of a process of the server apparatus which received the response with respect to mail is shown. The processing procedures and processing contents shown in FIGS. 22 to 28 are examples, and the processing of the present invention is not limited to such contents. In addition, A in the figure is a connector that connects the processes in the flowchart.

  The processing at the time of receiving the mail text, the processing at the time of receiving the pre-mail, and the processing at the time of receiving the response to the pre-mail are an example of the mail relay program of the server device of the present disclosure, and the processing of the mail relay system 90 shown in FIG. It is executed in each server device (S), (M1), (M2), (M3), (P1), (P2).

  (1) Destination unit management processing when receiving email (Figure 22)

  In this management process, for example, the most upstream server apparatus (S) at the time of mail transmission or the downstream server apparatus that received the mail text in response to the necessity of sending the mail text to the pre-mail is executed. Shows the processing to be performed. In this process, management is performed in units of mail destinations, and the sender that sent the mail or pre-mail earlier is preferentially processed.

  The server apparatus that has received the mail extracts the previous transmission source of the mail 60 as “src” (S61). This “src” is, for example, an area for holding work data indicating the server device of the mail source set in the mail text, and may be set in the storage unit 66, for example. Further, the message ID is extracted from the mail 60 to “M-ID” (S62). This “M-ID” is an area for storing the message ID of the mail identification information, and may be set in the transmission destination management folder 54, for example.

  Destination management information is extracted from a mail whose target is the same text as the received mail (S63). Specifically, the transmission destination management table 56 is detected, and there is an instance (management data) of the transmission destination management table in which the “Message-ID” stored in the server device matches the extracted “M-ID”. Is determined (S64). When there is no transmission destination management instance (YES in S64), that is, when the mail 60 indicated by this message ID is received for the first time, a transmission destination management instance of this message ID is generated in the transmission destination management table (S65). . In this case, the extracted “M-ID” is registered in the “Message-ID” area. In the “reception source” area, for example, “the most upstream” indicating that the server device receives mail and performs transmission control of the mail text by the pre-mail in the mail relay route as described above is registered.

  The server device develops the mailing list registered in the server device based on the destination information set in the received mail, and generates a “transmission destination list” using the transmission destination information (S66). The “user” information and “server” information of the destination are extracted as “destination information” in the destination list (S67), and the pre-mail “Pre-mail” is transmitted for each destination “server” (S68). .

  Here, the destination information extraction processing in step S67 is an example of pre-mail transmission preparation processing, and includes, for example, analysis of mail destination server information, as shown in FIG.

  In the destination information extraction process, the generated “destination list” is searched, a record that matches the “destination information” is extracted (S81), and it is determined whether there is a record (S82). In this process, for example, it is determined whether or not a transmission destination is already registered in the transmission destination list. If there is a record (NO in S82), the destination information extraction process is terminated. If there is no record (YES in S82), it is determined whether it is the local server or another server (S83). In determining whether the server is the local server or the other server, for example, the destination of the received mail is determined based on whether the information processing device name used by each user and the local server are specified.

  Referring to the registered contents in the “server” area of the extracted record, when a server other than the server device to which the transmission destination is targeted is specified (NO in S83), the transmission destination is determined to be another server. Then, “user” information is registered in the “transmission destination” of the transmission destination list, and “server” information is registered in the “server” area (S84). The “transmission necessity” of the mail text is set to “undecided” since the pre-mail response has not been received from the target server device. Then, destination information is added to the destination (transmission destination) of “pre-mail” for each transmission destination “server” (S85).

  Further, when the destination is the local server (YES in S83), “user” is displayed in the “sender” area of the destination list, “server name” (local server name), “transmission required” is displayed in the “server” area. “Termination” is set in the “No” area (S86). The “termination” of this “transmission necessity” area indicates that it is not necessary to relay the mail downstream from the target server device.

  When the destination information extraction process in the destination list is performed for all the destination information registered in the server apparatus, the process proceeds to step S68, and a pre-mail is transmitted to the extracted destination.

  In addition, for example, when the pre-mail is transmitted / received to / from the upstream server apparatus as described above, the destination information is acquired, and the destination management instance already exists (NO in S64), the mail receiving source It is determined whether or not the scheduled destination matches the mail transmission source (S69). Specifically, it is determined whether or not the “reception source” data of the transmission destination management instance matches the transmission source extracted from the mail stored in “src” (S69). That is, for the mail received this time, the consistency of the “reception source” information is determined with respect to whether or not the transmission destination management instance is applied. If the receiving sources do not match (NO in S69), the process proceeds to step S66.

  If they match (YES in S69), it is determined whether the server itself requires the mail text 78 (S70). Here, for example, when the target server device is a destination server device, or when the necessity of transmission by pre-mail is confirmed with the downstream server device, the “reception necessity” is “ Judgment is made based on whether or not “required” is set. If “reception required” is not “required” (NO in S70), the process proceeds to step S66. Further, when “reception necessity” is “necessary” (YES in S70). The destination management instance is updated to the setting that has received the mail (S71). Specifically, for example, “M-ID” is registered in the “Message-ID” area, and the “reception source” area is set to “most upstream”.

  Then, with respect to the destination information in the destination list, the process proceeds to extraction processing of “user” information and “server” information when requesting transmission of the mail text (S72), and is designated as the destination based on the extracted information. A mail is transmitted for each “server” (S73).

  In the information extraction processing in step S72, as shown in FIG. 24, it is determined whether the transmission destination is addressed to the own server (S91). Specifically, it is determined whether the “server” information indicates the own server among the extracted records of information registered in the transmission destination list (S91). If it is the server itself (YES in S91), the received mail is posted to the corresponding user's personal mailbox 62 (S94). If it is another server (NO in S91), for example, it is determined whether or not the downstream transmission destination server apparatus requests the mail text (S92). That is, it is determined whether the “transmission necessity” area of the extracted record in the transmission destination list is “necessary”. If the “transmission request” is “necessary” (YES in S92), the destination information is added to the destination of “mail” for each destination “server” area in the destination list and updated (S93).

  These information extraction processes are repeated for all the destinations, and the process proceeds to step S73. In FIG. 22, the process proceeds to S66 after the process of S73. However, the present invention is not limited to this. For example, after the mail transmission process (S73) to the destination server apparatus, the process by the mail reception may be terminated. Good. As a result, for example, when a server device that does not have a pre-mail transmission / reception function is included in the mail relay route, mail can be sent even when an instance of the destination list is generated by receiving mail from this server device. can do.

  (2) Destination unit management processing when a pre-mail is received (FIG. 25)

  In this process, for example, when a pre-mail is received from an upstream server device, the first pre-mail or the transmission source of the first mail is processed with priority.

  From the received pre-mail transmission signal, the server device information of the previous transmission source is extracted to “src” (S101), and the message ID is extracted to “M-ID” (S102).

  The destination management information is extracted from the mail that targets the same text as the received pre-mail (S103). Specifically, as in step S63 (FIG. 22), it is determined whether or not there is an instance (management data) of the transmission destination management table in which “Message-ID” matches the extracted “M-ID”. This is performed (S104). If there is no transmission destination management instance (YES in S104), a transmission destination management instance of this message ID is generated in the transmission destination management table (S105). In this case, for example, the extracted “M-ID” is registered in the “Message-ID” area, “src” is registered in the “reception source” area, and “undecided” is displayed in the “reception necessity” area. sign up. For example, a response (Pre-ACK) is returned to the sender of the pre-mail (S106). In this case, since it is not determined whether transmission is necessary, “undecided” is set.

  The server device develops a mailing list registered in the server device based on the destination information set in the mail, and generates a “transmission destination list” using the transmission destination information (S107). The “user” information and “server” information of the destination are extracted as “destination information” in the destination list (S108), and the pre-mail “Pre-mail” is transmitted for each destination “server” (S109). .

  Here, the destination information extraction processing in step S108 includes, for example, analysis of mail destination server information, as shown in FIG.

  In the destination information extraction process (S108), the generated “destination list” is searched, a record that matches the “destination information” is extracted (S121), and it is determined whether there is a record (S122). In this process, for example, it is determined whether or not a transmission destination is already registered in the transmission destination list. If there is a record (NO in S122), the destination information extraction process is terminated, and if there is no record (YES in S122), it is determined whether it is the local server or another server (S123). In determining whether the server is the local server or the other server, for example, the destination of the received mail is determined based on whether the information processing device name used by each user and the local server are specified.

  Referring to the registered contents in the “server” area of the extracted record, if a server other than the server device targeted for the transmission destination is specified (NO in S123), the transmission destination is determined to be another server. Then, “user” information is registered in the “transmission destination” of the transmission destination list and “server” information is registered in the “server” area (S124). The “transmission necessity” of the mail text is set to “undecided” since the pre-mail response has not been received from the target server device. Then, destination information is added to the destination (transmission destination) of “pre-mail” for each transmission destination “server” (S125).

  If the destination is the local server (YES in S123), “user” is displayed in the “sender” area of the destination list, “server name” (local server name) is displayed in the “server” area, “Termination” is set in the “No” area (S126).

  The server device determines whether or not the mail text has been received (S127). If the mail has been received (YES in S127), the mail text is posted to the personal mailbox corresponding to “user” (S128). In the confirmation that the mail text has been received, for example, it is determined whether or not the “reception source” of the transmission management instance is “most upstream”. When the mail text has not been received (NO in S127), the extraction process is performed for the next destination.

  When the destination information extraction process in the destination list is executed for all the destination information registered in the server apparatus, the process proceeds to step S109. And with respect to the extracted destination information, a server apparatus transmits a pre-mail for every server of a transmission destination (S109).

  Further, it is determined whether or not it is necessary to receive the mail text on the server itself (S110). If it is not yet determined (YES in S110), the destination list is searched, and “transmission necessity” ends. Alternatively, a “necessary” record is extracted. (S111). Further, when “reception necessity” is other than undetermined (NO in S110), for example, it indicates that a response to the upstream server device has been transmitted, and thus the processing is terminated.

  It is determined whether or not there is a record indicating “end” or “necessary” in the transmission destination list (S112). If there is no record (YES in S112), the process is terminated. If there is a record (NO in S112), the "reception necessity" area is updated to "required", and a response (Pre-ACK) is returned to the upstream server device (S113).

  If the server device already has a transmission management instance (NO in S104), it refers to the “reception necessity” area and determines whether the server does not need the mail text (S114). When it is undecided whether or not the mail text should be transmitted (YES in S114), the mail management apparatus sets the mail reception completion to the transmission destination management instance (S115). At this time, “reception source” is set to “src”, and “reception necessity” is set to “undecided”. If the mail text is not required (NO in S114), a response (Pre-ACK) with “Necessity of transmission” as “No” is returned (S116).

  (3) Destination unit management processing when a response to the pre-mail is received (FIG. 27)

  In this process, for example, a case where a pre-mail response including the necessity of transmission of the mail text is received from the downstream server device is shown, and the first pre-mail or mail transmission source is processed with priority. .

  The server apparatus determines whether the necessity of the mail text is “undecided” for the downstream server apparatus that has transmitted the pre-mail response (Pre-ACK) (S131), and if it is undecided (YES in S131) In the case of), the process is terminated, and for example, it waits for a new response.

  If the transmission necessity is not yet determined (NO in S131), “Message-ID” is extracted from the pre-mail response and held in “M-ID”, and “transmission necessity” information is extracted and stored, for example, It is held in the “necessity” area set in the section (S132). The server device searches the transmission destination management table in which the pre-mail response matches the “Message-ID”, and reads out the transmission destination management instance (S133). If there is no corresponding “Message-ID” transmission destination management instance (NO in S134), the process ends.

  When the transmission destination management instance is read (YES in S134), “server” information is extracted for the destination information included in the pre-mail response, as shown in FIG. 28 (S135). Then, “transmission necessity” is set in the transmission destination list. At this time, for example, “necessary” or “not required” is set in the “transmission necessity” area for the server information record corresponding to the “server” area (S136).

  The server device refers to whether or not the “reception source” area in the transmission destination management instance is “most upstream” indicating that the mail has been received, and determines whether or not the mail text has been received (S137). If the mail text has not been received (NO in S137), it is determined whether or not it is necessary to receive the mail text on its own server (S138). If it is undecided (YES in S138), it is determined whether or not the transmission source of the received pre-mail response requires the mail text (S139). In this determination, for example, the extraction result in step S136 may be referred to.

  When the mail text is required (YES in S139), the server device transmits a pre-mail response requesting transmission of the mail text to the server device further upstream (S140). In this pre-mail response, a response in which the “transmission necessity” area is set to “necessary” is transmitted to the “reception source” of the transmission management table indicating the server apparatus that has transmitted the pre-mail to the server apparatus. Then, “necessary” is set in the “reception necessity” area of the transmission management table. For example, if at least one mail text request is received from the downstream server apparatus, the server apparatus sends a mail text transmission request to the upstream server apparatus.

  When the transmission source of the pre-mail response does not request transmission of the mail text (NO in S139), a transmission source record whose “transmission necessity” is undetermined is extracted (S141). If there is no corresponding record and all the senders do not need the mail text (NO in S142), the server device sets “transmission necessity” to “no” for the upstream server device. A pre-mail response is transmitted (S143). At this time, “No” is set in the “reception necessity” area of the transmission management table.

  If the server apparatus has received the mail text (YES in S137), if the sender of the received pre-mail response has requested the mail text (YES in S144), the mail text is transmitted to this sender. (S145).

  [Features and effects of the second embodiment]

  (1) According to such a configuration, it is possible to prevent duplicate mails from being sent to the same destination in the mail sending process in which the mailing list is designated as the destination.

  (2) Regarding the server device that relays the mail, the necessity of the mail text up to the transmission destination is determined prior to the transmission of the mail text, so that it is possible to prevent the mail from being sent unnecessarily between the server devices.

  (3) Since the destination information is managed in cooperation between the server devices, it is possible to prevent the mail from being transmitted.

  (4) The present invention shows means for avoiding receiving a plurality of the same mails for an electronic mail mailing list. Therefore, in this server device, prior to transmission of the mail text, an instance of the transmission management table is generated and managed according to the uniqueness determination information of the mail text of the received mail or pre-mail transmission signal.

  (5) This server device develops the destination information in the mailing list held by itself based on the destination of the received mail or pre-mail transmission signal. The necessity of transmission of the mail text is managed for each destination in the destination list of the instance of this destination management table.

  (6) By receiving the necessity of transmission of the mail text by the pre-mail transmission response from each destination in the destination list, and collecting the necessity of transmission in the destination list, it is possible for the server device in the upstream direction of the mail relay route. In response to the pre-mail transmission signal, whether or not mail transmission is necessary is transmitted.

  (7) When the mail text is received from the upstream server device, the mail text is transmitted to the destination in the transmission destination list whose transmission necessity is “necessary”.

  (8) The same mail can be prevented from being repeatedly transferred in the mail receiving side POP server and the receiving side Client.

  (9) In the server device of the present invention, in the mail relay process, the downstream relay server is inquired about the necessity of the mail text by the pre-mail, and the mail text is sent only to the downstream server apparatus that responded “required”. Send.

  (10) According to the server device or the mail relay program, useless relaying of the mail having the same content is reduced without instructing the mail sender or the upstream relay server to participate in the mail recipient's mailing list.

  [Third Embodiment]

  Next, FIG. 29 is referred about 3rd Embodiment. FIG. 29 shows another configuration example of the mail relay system. The configuration illustrated in FIG. 29 is an example, and the present invention is not limited to such a configuration.

  The mail relay system 200 shown in FIG. 29 relays an electronic mail between the electronic device “a” on the mail sender side and the electronic devices “x”, “y”, “z”, “w” on the mail receiving side. It is carried out. As described above, the mail relay system 200 includes the transmission-side server device (S), the reception-side server devices (P1) and (P2), and the relay server devices (M1), (M2), and (M3). In addition to the mail relay system 90 (FIG. 12), a relay server device (M4) is arranged. The relay server device (M4) stores, for example, a mailing list (m4-list) 206 in which the mailing list (m32-list) 210 stored in the relay server device (M3) is registered as destination information.

  In the transmission mail 202, a mailing list (m4-list) 206 is designated as a transmission destination. With such a configuration, the server apparatus (M4) receives the pre-mail (9) (Pre-mail # 9) 204 from the server apparatus (S) and sends it to the server apparatus (M3) according to the mailing list (m4-list). The pre-mail (10) (Pre-mail # 10) 208 is transmitted.

  The mailing list (m32-list) 210 stored in the server apparatus (M3) includes, for example, “z @ P2” and “w @ P2” as transmission destination information. Among these, the transmission destination “z @ P2” is registered in both the mailing list (m3-list) 96 and the mailing list (m32-list) 210. In such a configuration, the server apparatus (M3) transmits / receives the pre-mail (11) (Pre-mail # 11) 212 to / from the downstream server apparatus (P2) on the mail relay path, and relays it. To determine whether or not to send the email text.

  Next, an example of relay processing of pre-mail and mail text by the mail relay system will be described with reference to FIGS. 30, 31, 32, 33 and 34. FIG. FIG. 30 is a diagram showing a sequence of the mail relay processing example, and FIGS. 31 to 34 show an example of the generation or update state of the transmission destination management table in the server apparatuses (M3), (M4), and (P2). ing. The configurations and processing procedures or processing contents shown in FIGS. 30 to 34 are examples, and the present invention is not limited to such configurations.

  As shown in FIG. 30, when the electronic device “a” on the sender side transmits a mail 202 (S151), the server apparatus (S) receives this mail 202 and extracts a message ID. The server apparatus (S) refers to the transmission destination management folder 54 (FIG. 7), and if there is no instance of the transmission destination management table 56 corresponding to this message ID, the server apparatus (S) stores information about this message ID in the transmission management destination folder 54. Generate an instance of the destination management table.

  Then, as described above, the server apparatus (S) transmits the pre-mail (1) (Pre-mail # 1) of the transmission destination “x @ P1” to the transmission destination server (P1) (S152). ). Steps S152 to S166, which are pre-mail transmission / reception processes of the mail relay system 200, may be performed in the same manner as steps S32 to S46 (FIG. 14) showing the mail relay process described above, and will not be described separately.

When the server apparatus (M4) receives the pre-mail (9) from the server apparatus (S) (S167), the server apparatus (M4) extracts the message ID and holds an instance of the transmission destination management table corresponding to the message ID. Check if it exists. For example, as illustrated in FIG. 33A, the server apparatus (M1) generates an instance of the transmission destination management table 240. The server apparatus (M4) registers the server apparatus (S) in the reception source area 241 and is registered in the mailing list (m32-list) according to the transmission destination information described in the pre-mail (9) in the transmission destination list 243. The transmission destination information 244 is registered.

  Further, the server apparatus (M4) transmits a pre-mail (10) (Pre-mail # 10) to the server apparatus (M3) regarding “m3 @ M3” of the transmission destination information 244 (S168).

  When the server apparatus (M3) receives the pre-mail (10) from the server apparatus (M4) (S168), the server apparatus (M3) extracts the message ID and holds an instance of the transmission destination management table corresponding to the message ID. To check. Since the server apparatus (M3) has already received the pre-mail (3) corresponding to the same message ID from the server apparatus (S) (S154), the server apparatus (M3) has an instance of the transmission destination management table 220 as shown in FIG. ing. Then, as shown in FIG. 32C, the server device (M3) updates the reception source area 221 to the server device (M4) for the received pre-mail (10).

  The server device (M3) reads the stored mailing list (m32-list) based on the transmission destination information of the pre-mail (10). At this time, for example, since the transmission destination “z @ P2” has already transmitted the pre-mail (8), the server apparatus (M3) does not transmit the pre-mail having the same content again. Therefore, the server apparatus (M3) transmits a pre-mail (11) (Pre-mail # 11) for the transmission destination “w @ P2” to the server apparatus (P2) (S169). Also, since the server apparatus (M3) does not need to transmit the mail text for the pre-mail response from the server apparatus (P1), for example, the “reception necessity” area 222 shown in FIG. Update to Then, a response (Pre-ACK # 10) is sent to the server apparatus (S) set as the reception source to determine whether the reception is necessary or not (Pre-ACK # 10) (S170).

  When the server apparatus (M4) receives the response from the server apparatus (M3), as shown in FIG. 33B, the transmission necessity list is changed to “No” in the transmission destination list 243. The server apparatus (M4) changes the reception necessity area 242 to “No”, and returns a response (Pre-ACK # 9) of transmission necessity “No” to the server apparatus (S) (S171).

  The server apparatus (P2) that has received the pre-mail (8) generates a transmission destination management table 180 for the extracted message ID, as shown in FIG. 34A, and is set to the pre-mail (8) in the transmission destination list 183. The transmission destination “z” is registered. Since this transmission destination “z” is connected to the server apparatus (P2), the “transmission necessity” area is set to “end”. Since the server device (P2) does not have the mail text data, the “reception necessity” area 182 is set to “necessary”.

  When the server apparatus (P2) receives the pre-mail (11), the server apparatus (P2) reads the transmission destination management table 180 and registers the transmission destination “w”. In the same manner as described above, “end” is set in the “transmission necessity” area 250.

  Then, the server device (P2) returns a response (Pre-ACK # 8) with “required” as to whether transmission is required for the pre-mail (8) to the server device (M3) (S172). The server apparatus (M3) that has received the response to the pre-mail (8), as shown in FIG. 32D, for the area of the server apparatus (P2) in the transmission destination list 223, the transmission necessity area 228 for the transmission destination “z”. Is updated to "necessary". In this case, although the transmission necessity for the transmission destination “w” is still “undecided”, the transmission necessity is changed to “necessary” for at least one server apparatus (P2). Is updated to "necessary". Then, the server device (M3) uses, for example, the pre-mail (3) that has not returned a response indicating whether or not transmission is required, and determines whether or not transmission is required with respect to the server device (S) storing the mail text. A response “Pre-ACK # 3” is returned (S173).

  Further, the server device (P2) returns a response (Pre-ACK # 11) with “required” as to whether or not the pre-mail (11) needs to be transmitted to the server device (M3) (S174). The server apparatus (M3) that has received this response updates the transmission necessity area 230 of the transmission destination “w” in the transmission destination list 223 to “necessary”, as shown in FIG. 32E. At this time, since the server apparatus (M3) has already requested the upstream server apparatus (S) to transmit the mail text, for example, in order to transmit the mail text to the server apparatus (P2). Also, the request for sending the mail text is not made again. Then, when the necessity of transmission of the mail text by sending / receiving the pre-mail is determined, the server apparatus (S) transmits the mail text 202 to the relay server apparatus (M3) (S175). The relay server device (M3) that has received the mail text 202 from the server apparatus (S) transmits the mail text 202 to the receiving server apparatus (P2) according to the transmission destination management table (S176).

  According to such a configuration, it is possible to prevent the same mail content from being transferred repeatedly by confirming whether or not the mail text needs to be transmitted by sending and receiving the pre-mail and determining the minimum relay route. The relay path of the mail text can be determined on the receiving server side or in the middle of the mail relay path.

  [Fourth Embodiment]

  Next, a fourth embodiment will be described with reference to FIGS. 35 and 36 show an example of processing by mail reception, and FIGS. 37 and 38 show an example of processing by reception of a pre-mail response. In the figure, A, B, and C are connectors that connect the flowcharts.

  (1) Destination unit management processing when receiving email (Figs. 35 and 36)

  This management process is an example of the mail relay method or mail relay program of the present disclosure, and performs priority processing for the first mail in the management of each destination. In the mail relay system, regardless of whether or not the pre-mail has been received, the server device that has received the mail text serves as the relay source server device, and transmits the pre-mail to the downstream server device and manages the transmission of the mail text. Do. In this case, for example, the server device that has received the mail text outputs a pre-mail response indicating that transmission of the mail text is unnecessary (transmission necessity “no”) to the server device upstream of the mail relay path.

  As shown in FIG. 35, the server apparatus that has received the mail text extracts information such as the mail transmission source and message ID, and whether or not there is a transmission destination management instance (processing information) in the transmission destination management table for this mail. Is confirmed (S181 to S184). These processes may be performed in the same manner as the above-described S61 to S64 (FIG. 22), for example.

  If there is no destination management instance for the received mail (YES in S184), a destination management table is generated, information on the destination list to be stored is extracted, a pre-mail transmission process is performed for the destination in the destination list, etc. S185 to S188). Such processing steps S185 to S188 may be performed in the same manner as, for example, steps S65 to S68 (FIG. 22) and steps S81 to S87 (FIG. 23).

  Further, when the transmission destination management instance of the transmission destination management table corresponding to the extracted message ID is stored (NO in S184), it is confirmed whether the mail body has been recorded in the transmission destination management instance. (S189). For example, in order to confirm whether or not the server apparatus that received the mail text is set as the mail relay source, it is determined whether the “reception source” area of the transmission destination management table is updated to “most upstream”.

  If the received mail body has been recorded in the destination management instance (YES in S189), the process proceeds to step S186 to perform transmission destination management and pre-mail or mail body transmission processing.

  Further, when the reception of the mail text is not recorded in the transmission destination management instance (NO in S189), it is determined whether or not the reception source registered in the transmission destination management instance matches the transmission source of the received mail ( S190). For example, the information of the “reception source” area is compared with the transmission destination information stored in “src”. If the information in the “reception source” area matches the transmission destination information in “src” (YES in S190), the transmission destination management instance is updated and the received mail is registered (S191). For the destination information, “user” information and “server” information extraction processing (S192) when requesting transmission of the mail text is performed, and the mail text is transmitted for each destination server (S193). Transition. The process of step S192 may be performed in the same manner as step S72 (FIGS. 22 and 24), for example.

  In addition, when the “reception source” area does not match the transmission source information of the extracted mail (NO in S190), it is determined whether the reception necessity area of the mail text registered in the transmission destination management instance is “necessary”. (S194). Specifically, for example, it is determined whether or not the “reception necessity” area is “undecided”. If it is not “undetermined” (NO in S194), the process proceeds to S191. If the “reception necessity” area is “undecided” (YES in S194), a pre-mail response (Pre-ACK) is sent back to the receiver registered in the transmission management instance as “necessity of transmission”. (S195), the process proceeds to step S191. For example, if the mail text is received from a server device other than the server device set as the receiving source (NO in S190), and the “required” of the mail is “necessary” (YES in S194). , Preventing re-reception of emails with the same content.

  (2) Processing by receiving pre-mail response (Fig. 37, Fig. 38)

  This process is an example of transmission management of the mail text in response to a pre-mail response including the necessity of transmission of the mail text from the downstream server device.

  The server apparatus determines whether the necessity of the mail text is “undecided” for the downstream server apparatus that is the transmission source of the pre-mail response (Pre-ACK) (S201), and the necessity of transmission is not yet determined. In this case (NO in S201), transmission destination management is performed for each mail destination. About the process shown to step S201-step S206, what is necessary is just to carry out similarly to the above-mentioned step S131-step S136 (FIG. 27, FIG. 28), for example, and abbreviate | omits concrete description.

  In determining whether the server device has received the mail text, as described above, if the server device has received the mail text (YES in S207), it responds to the transmission necessity response from the downstream server device. The mail text is transmitted (S214, S215). Further, in the server device that has not received the mail (NO in S207), the “reception necessity” of the transmission destination management instance is confirmed, and it is confirmed whether the transmission source of the pre-mail response requires the mail text (S208). . For example, it is determined whether or not the “reception necessity” area is “undecided”, and if it is undecided (YES in S208), it is determined whether or not the “transmission necessity” of the pre-mail response is necessary (S209). ).

  When the mail text is required (YES in S209), the server device transmits a pre-mail response requesting transmission of the mail text to the server device further upstream (S210).

  When the transmission source of the pre-mail response does not request transmission of the mail text (NO in S209), a transmission source record whose “transmission necessity” is undetermined is extracted (S211). If there is no corresponding record and all the senders do not need the mail text (NO in S212), this server apparatus sets “transmission necessity” to “no” for the upstream server apparatus. A pre-mail response is transmitted (S213).

  As described above, the processing example when the pre-mail is received from the upstream server device may be performed in the same manner as the processing shown in FIGS. 25 and 26, and detailed description thereof is omitted.

  This fourth embodiment also has the same features as the first to third embodiments described above, and can provide the same effects.

  [Fifth Embodiment]

  In the fifth embodiment, transmission destination management by each server device is performed in units of transmission destination servers.

  FIG. 39 is referred to regarding the transmission destination management of the mail text. FIG. 39 is a diagram illustrating a configuration example of a transmission destination management table according to the fifth embodiment.

  The transmission destination management table 260 illustrated in FIG. 39 is set based on, for example, transmission destination information set in the received mail text. In the transmission destination management table 260, for example, a reception source area 261 indicating the reception source of mail or pre-mail, or a reception necessity area for recording whether or not the server apparatus having the transmission destination management table requires a mail text. 262. The reception necessity information set in the reception necessity area 262 is output information of a response instruction to the upstream server device as described above.

  The transmission destination management table 260 includes a transmission destination server list 264 for managing servers corresponding to the transmission destination, as well as a transmission destination list 263 for managing transmission destination information of the mail text. The transmission destination list 263 includes, for example, a transmission destination information area 266 that expands transmission destination information registered in a mailing list stored in the server device, and a server area 268 that expands server information corresponding to the transmission destination information. What is necessary is just to comprise. The transmission destination server list 264 manages the necessity of transmission of the mail text for each transmission destination server, and includes, for example, a server information area 270 and a transmission necessity area 272.

  The mail body relay process using the transmission destination management table 260 will be described with reference to FIGS.

(1) Destination management process when receiving mail (Figures 22 and 40)
In this management process, the server apparatus executes the process with priority given to the first pre-mail or the mail transmission source, and for example, performs management for each server apparatus as the transmission destination.

  Management processing at the time of mail reception may be performed in the same manner as, for example, steps S61 to S73 (FIG. 22) and steps S91 to S94 (FIG. 24) described above. In the management process at the time of mail reception by the server unit, among these processes, for example, the process shown in FIG. 40 is performed in the destination list destination information extraction process (S67 (FIG. 22)). Therefore, in the destination information extraction process, the transmission destination list 263 is searched, and a record that matches the destination information set in the mail is extracted (S221). When the mail destination information record is not registered in the transmission destination list 263 (YES in S222), it is determined whether or not the transmission destination is the local server (S223). For example, it is determined whether or not the “server” information set in the record of the destination (destination) information of the extracted mail specifies this server device.

  If another server apparatus is indicated (NO in S223), the destination information extracted in the transmission destination list 263 is registered (step S224). Specifically, for example, the user name of the destination information may be registered in the “transmission destination” area 266 and the server information may be registered in the “server” area 268. Then, destination information is added to the destination of the pre-mail for each destination server name (step S225). For example, the server name registered in the server area 268 of the transmission destination list 263 is registered in the transmission destination server list 264. This server name is registered for each server with respect to the destination information registered in the destination list 263. For example, when a plurality of destination information is connected to the same server, a common server name is registered. .

  Then, it is managed whether or not transmission of the mail text is requested for each registered server (step S226). This server device manages the response to the pre-mail transmitted for each server registered in the destination server list, and refers to the necessity information registered in the “transmission necessity” area 272. If the transmission necessity is “necessary” (S226), the destination information extraction process is completed, and the process proceeds to step S68. If the necessity of transmission is not “necessary” (NO in S226), the necessity of the mail text at the transmission destination is set to “undecided” (step S227). Then, the process proceeds to step S68.

  Further, when the destination server is designated as the destination server (YES in S223), the destination information is registered in the destination list 263 (step S228). In this case, since there is no downstream side of the mail relay path from this server device, for example, “end” is registered in the “transmission necessity” area 272. Then, the received mail text is posted to the personal mailbox corresponding to the user designated as the destination (S229).

  If the mail destination information record is registered in the destination list 263 (NO in S222), the destination information extraction process of this destination list is completed.

  (2) Destination management processing when pre-mail is received (FIGS. 41 and 42)

  In this management process, the server apparatus preferentially executes the process of the first pre-mail or the mail, whichever comes first. For example, the server apparatus manages each transmission destination server apparatus.

  The destination information such as the sender information, message ID, and mail destination is extracted from the received pre-mail (S231 to S233). And it is judged whether the instance of the transmission destination management table with which message ID corresponds is memorize | stored (S234). If there is no instance (YES in S234), a destination management instance is expanded using a mailing list or the like in the server device to generate a destination list. 41 may be performed in the same manner as the above-described steps S101 to S107 (FIG. 25).

  When the transmission destination list is generated, the destination information in the transmission destination list is extracted (S237). In this destination information extraction process, for example, as shown in FIG. 42, the destination list 263 is searched, and a record of destination information that matches the “destination information” in the mail text is extracted (S251). If there is a record (NO in S252), the destination information extraction process is terminated. If there is no record (YES in S252), it is determined whether or not the destination is connected to the local server (S253). . For example, when the destination is another server (NO in S253), “user” information is registered in the “transmission destination” of the transmission destination list and “server” information is registered in the “server” area 263 (S254), and for each server. The destination information of the pre-mail is added (S255).

  Then, for example, referring to the destination server list 264, it is determined whether the destination requests transmission of the mail text (S256). If so (YES in S256), this destination information extraction processing is performed. And the process proceeds to step S238 (FIG. 41). If the transmission necessity is not “necessary” (NO in S256), the necessity of the mail text at the transmission destination is determined to be undecided. For example, the transmission necessity of the transmission destination server list 264 is set to “undecided” (S257). ).

  When the destination information extraction processing is performed, a pre-mail is transmitted to each destination server (S238), and it is determined whether or not the scheduled destination of the mail body and the pre-mail sender match (S239). . In this process, for example, it is determined whether or not the mail is a pre-mail from a server device (scheduled destination) set as a mail receiving source. If they match (YES in S239), a transmission destination that requires the mail text is extracted (S240). For example, the server device searches the transmission destination server list 264 and extracts a record whose transmission necessity area 272 is “termination” or “necessary”. If this record does not exist (YES in S241), a pre-mail response in which transmission necessity is set to “undecided” is returned (S242).

  If there is a record (NO in S241), a pre-mail response in which transmission necessity is set to “necessary” is returned (S243).

  If the scheduled recipient of the mail body does not match the sender of the pre-mail (NO in S239), a pre-mail response with “no” as the necessity of transmission is returned (S244). If there is no destination management instance (NO in S234), it is determined whether or not the server itself requires a mail text (S245). If it is not necessary (YES in S245), mail reception completion is set in the transmission destination management instance, and the reception necessity area is set to “No” (S246).

  With such a configuration, it is possible to obtain the same effect as the above embodiment. In addition, by managing transmission destination information in units of connected server devices, it is possible to maintain the atomicity of necessity of transmission of downstream server devices for transmission destination information set in the mail text.

  [Sixth Embodiment]

  In the sixth embodiment, each server device constituting the mail relay system uses a transmission destination management table 260 (FIG. 39) for managing transmission destinations for each server. Regardless of whether or not the preceding pre-mail has been received, the server device that has received the mail is regarded as the most upstream server device, and transmission management of the mail text to the downstream server device is performed.

  The mail body relay process will be described with reference to FIGS.

  (1) Management process when receiving mail (Fig. 43, Fig. 44)

  This management process is an example of the mail relay method or mail relay program of the present disclosure, and the server device manages the transmission of the mail text in units of the destination server device, and gives priority to the first mail destination. The process is being executed.

  As shown in FIG. 43, the server apparatus that has received the mail text extracts information such as the mail transmission source and message ID, and whether there is a transmission destination management instance (processing information) in the transmission destination management table for this mail. Is confirmed (S271 to S274). These processes may be performed in the same manner as the above-described S61 to S64 (FIG. 22), for example.

  If there is no destination management instance for the received mail (YES in S274), a destination management table is generated, a destination list information extraction process to be stored, a pre-mail transmission process for a destination in the destination list is performed ( S275-S278). Such processing steps S275 to S278 may be performed in the same manner as, for example, steps S65 to S68 (FIG. 22) and steps S81 to S87 (FIG. 23).

  If the transmission destination management instance of the transmission destination management table corresponding to the extracted message ID is stored (NO in S274), it is confirmed whether the mail text has already been received (S279). In this process, for example, it is confirmed whether “most upstream” is set in the “reception source” area of the transmission destination management instance.

  If the mail has been received (YES at S279), the process proceeds to step S276 to perform transmission destination management and pre-mail or mail text transmission processing.

  If the mail has not been received (NO in S279), it is determined whether the reception source registered in the transmission destination management instance matches the transmission source of the received mail (S280). For example, the information of the “reception source” area is compared with the transmission destination information stored in “src”. If the information in the “reception source” area matches the transmission destination information in “src” (YES in S280), the transmission destination management instance is updated and the received mail is registered (S281). Then, with respect to the destination information about the destination list, extraction processing of “user” information and “server” information when requesting transmission of the mail text is performed (S282), and the mail text is transmitted for each destination server ( S283) and the process proceeds to S276. The extraction process in step S282 may be performed in the same manner as in step S72 (FIGS. 22 and 24), for example.

  If the “reception source” area does not match the extracted mail transmission destination information (NO in S280), it is determined whether or not the reception necessity of the mail text registered in the transmission destination management instance is “undecided” (S284). ). When it is not “indeterminate” (NO in S284), the process proceeds to S281. If the “reception necessity” area is “undecided” (YES in S284), a pre-mail response (Pre-ACK) is sent to the reception source registered in the transmission management instance as “necessity of transmission”. (S285), the process proceeds to step S281.

  (2) Processing by receiving pre-mail response (Fig. 45, Fig. 46)

  This processing is an example of processing when priority processing is performed on the transmission source of the first-arrival mail in the management for each destination server when the pre-mail response is received from the downstream server device.

  The server apparatus determines whether the necessity of the mail text is “undecided” for the pre-mail response (Pre-ACK) (S291). If the necessity of transmission is not undecided (NO in S291), the server apparatus Manage the destination of the mail text. About the process shown to step S291-step S296, what is necessary is just to carry out similarly to the above-mentioned step S131-step S136 (FIG. 27, FIG. 28), for example, and abbreviate | omits concrete description.

  When determining whether or not the server has received the mail text, as described above, if the server apparatus has received the mail text (YES in S297), it responds to the transmission necessity response from the downstream server device. Then, the mail text is transmitted (S304, S305). In the server device that has not received the mail (NO in S297), the “reception necessity” of the transmission destination management instance is confirmed, and it is confirmed whether or not the reception of the mail text at the own server is undecided (S298). . For example, it is determined whether or not the “reception necessity” area is “undecided”, and if it is undecided (YES in S298), it is determined whether or not the “transmission necessity” of the pre-mail response is necessary (S299). ).

  When the mail text is required (YES in S299), the server device transmits a pre-mail response requesting transmission of the mail text to the server device further upstream (S300).

  When the transmission source of the pre-mail response does not request transmission of the mail text (NO in S299), a transmission source record whose “transmission necessity” is undetermined is extracted (S301). If there is no corresponding record and all the senders do not need the mail text (NO in S302), this server device sets “transmission necessity” to “no” for the upstream server device. A pre-mail response is transmitted (S303).

  As described above, the processing example when the pre-mail is received from the upstream server device may be performed in the same manner as the processing shown in FIGS. 27 and 28, and detailed description thereof is omitted.

According to such a configuration, the same effect as the fourth embodiment described above can be obtained, and transmission management of pre-mail and mail text is performed in units of server devices, so that transmission destination information set in the mail text and Information on necessity of transmission of the downstream server device can be maintained.

  Next, the following additional notes will be disclosed with respect to the embodiment including the above-described examples. The present invention is not limited to the following supplementary notes.

(Appendix 1) A server device for relaying electronic mail,
A communication unit that includes mail identification information that identifies the content of the mail text between the upstream relay source server devices connected to the network, and that transmits and receives a pre-mail for confirming whether the mail text needs to be transmitted;
A storage unit for storing the mail text or the mail identification information;
A control unit that determines whether or not transmission of the mail text is necessary from the mail identification information, and outputs a response instruction indicating whether transmission of the mail text is necessary or not to the relay source server device;
A server device comprising:

(Additional remark 2) The said communication part transmits the said pre-mail with respect to the downstream relay destination server apparatus registered,
The control unit receives the response instruction indicating whether transmission is necessary from the relay destination server device, and causes the relay destination server device that has received the transmission request to transmit the mail text. The server apparatus of description.

(Additional remark 3) The said control part determines whether the mail identification information of the received said pre-mail, and the said mail text or the said mail identification information correspond, The said mail text with respect to the said relay origin server apparatus The server device according to appendix 1 or 2, wherein a response indicating whether transmission is necessary is made.

(Additional remark 4) The said memory | storage part memorize | stores the transmission destination list | wrist including any one or both of the address information of the said relay destination server apparatus, the transmission destination information of the said email,
4. The server device according to any one of appendix 1 to appendix 3, wherein the control unit receives the transmission necessity response from the relay destination server device to generate or update the transmission destination list.

(Additional remark 5) The said control part produces | generates the said transmission list based on the mailing list in which the transmission destination information of the said email and the address information of one or several said relay destination server apparatus were registered, 4. The server device according to 4.

(Supplementary Note 6) Based on the received destination information of the pre-mail or the mail text, the control unit determines that the received mail text is the destination of the mail when the server device is a mail destination server. The server device according to any one of appendix 1 to appendix 6, wherein the server device is transmitted to the communication terminal device.

(Appendix 7) A mail relay program to be executed by a computer mounted on a server device that relays electronic mail,
Between the upstream relay source server devices connected to the network, including mail identification information for specifying the content of the mail text, sending and receiving a pre-mail for confirming the necessity of transmission of the mail text,
Storing the mail text or the mail identification information in a storage unit;
Determining whether the mail text needs to be transmitted from the mail identification information, and outputting a response instruction indicating whether the mail text needs to be transmitted to the relay source server device;
A mail relay program that allows a computer to execute functions.

(Appendix 8) The pre-mail is transmitted to the registered downstream relay server device,
8. The mail relay according to appendix 7, wherein the computer executes a function of receiving the response instruction indicating whether transmission is necessary from the relay destination server apparatus and causing the relay destination server apparatus that has received the transmission request to transmit the mail text. program.

(Additional remark 9) It is determined whether the mail identification information of the received pre-mail matches the mail text or the mail identification information, and a response indicating whether the mail text needs to be transmitted is sent to the relay server apparatus The mail relay program according to appendix 7 or 8, which causes a computer to execute the function to be executed.

(Supplementary Note 10) A destination list including any one or both of the address information of the relay destination server device and the destination information of the e-mail is stored in the storage unit,
The mail relay program according to any one of appendix 7 to appendix 9, which causes a computer to execute a function of generating or updating the destination list in response to a transmission necessity response from the relay destination server device.

As described above, the preferred embodiments and the like of the server device and the mail relay program have been described. However, the present invention is not limited to the above description, and is described in the claims or implements the invention. It goes without saying that various modifications and changes can be made by those skilled in the art based on the gist of the invention disclosed in the embodiments, and such modifications and changes are included in the scope of the present invention.

2, 20, 22, 24, 40 Server device 3 Other server device 4 Communication control unit 6 Storage unit 8 Control unit 10, 90, 200 Mail relay system 12, 14, 16, 18 PC
26, 60 Mail 28, 52 Mailing list 30, 31, 32, 80, 98-112, 204, 208, 212 Pre-mail 33, 78 Mail body 34 Header part 35 Message ID
36, 133, 143, 153, 163, 173, 183, 243, 263 Destination list 37, 144, 146, 154, 164, 174, 176, 178, 184, 244, 266 Destination information area 38 Server information area 39 228, 230, 250, 272 Transmission necessity information area 42 Pre-mail reception unit 44 Mail reception unit 46 Pre-mail transmission unit 48 Mail transmission unit 50 Mailing list folder 54 Destination management folder 56, 120, 130, 140, 150, 160 , 170, 180, 220, 240, 260 Destination management table 58 Relay folder 62 Personal mailbox 81 Transmission necessity 82 Transmission response S Transmission side server device P1, P2 Reception side server device M1, M2, M3 Relay server device 92 94, 96, 206, 10 Mailing List 122 Message ID Area 124 Pre-Mail Receiving Area 126, 132 Receiving Necessary Area 128 Destination List Area 134, 136, 138 Destination Area 141, 151, 161, 171, 181, 221, 241 Receiving Area 126 , 132, 142, 152, 162, 172, 182, 222, 242 Reception necessity area 264 Destination server list 268 Server area 270 Server information area

Claims (5)

A server device that relays electronic mail,
A communication unit that includes mail identification information that identifies the content of the mail text between the upstream relay source server devices connected to the network, and that transmits and receives a pre-mail for confirming whether the mail text needs to be transmitted;
A storage unit for storing the mail text or the mail identification information;
A control unit that determines whether or not transmission of the mail text is necessary from the mail identification information, and outputs a response instruction indicating whether transmission of the mail text is necessary or not to the relay source server device;
A server device comprising: The communication unit transmits the pre-mail to the registered downstream relay destination server device,
The control unit receives the response instruction indicating whether transmission is necessary from the relay destination server device, and causes the relay destination server device that has received the transmission request to transmit the mail text. The server device described in 1.   The control unit determines whether the received mail identification information of the pre-mail matches the mail text or the mail identification information, and determines whether the mail text needs to be transmitted to the relay source server device. The server device according to claim 1, wherein a response is made. The storage unit stores a destination list including any one or both of address information of the relay destination server device, destination information of the e-mail,
4. The server device according to claim 1, wherein the control unit receives the transmission necessity response from the relay destination server device, and generates or updates the transmission destination list. 5. A mail relay program to be executed by a computer mounted on a server device that relays electronic mail,
Between the upstream relay source server devices connected to the network, including mail identification information for specifying the content of the mail text, sending and receiving a pre-mail for confirming the necessity of transmission of the mail text,
Storing the mail text or the mail identification information in a storage unit;
A mail relay program for causing a computer to execute a function of determining whether or not to transmit the mail text from the mail identification information and outputting a response instruction indicating whether the mail text needs to be transmitted to the relay source server apparatus.

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