WO2001020855A1

WO2001020855A1 - Electronic mail system, and computer readable recorded medium on which electronic mail program is recorded

Info

Publication number: WO2001020855A1
Application number: PCT/JP1999/005048
Authority: WO
Inventors: Etsuo Tsuchiya
Original assignee: Fujitsu Limited
Priority date: 1999-09-16
Filing date: 1999-09-16
Publication date: 2001-03-22

Abstract

Clients (200A to 200D) are provided with storage units (205A to 205D) for storing information on sent electronic mails, and stop sending a new electronic mail when a text identical to that contained in the new electronic mail is stored in the storage units (205A to 205D). As a result, duplicate sending of an electronic mail containing the identical text is avoided. A mail server (300) judges, when it receives a forwarded electronic mail MAILAB containing a text and an identifier attached to the text from a client (200B), whether or not the identifier is identical to one of those of the electronic mail received in the past. If this judgment result shows YES, the mail server (300) issues no reception notice to the client (200D) which the destination of the electronic mail. As a result, the same client (200D) does not receive the same reception notices of electronic mails containing the identical text.

Description

Description E-mail system, client used in e-mail system, mail server used in e-mail system, and computer-readable recording medium that self-records e-mail program

Technical field

The present invention relates to an e-mail system used for sending / receiving e-mail, a client used for the e-mail system, a mail server used for the e-mail system, and a computer-readable recording medium recording an e-mail program. In particular, it is used for e-mail systems, clients used in e-mail systems, and e-mail systems that can improve network use efficiency, user convenience, and memory use efficiency of mail servers. The present invention relates to a mail server and an electronic mail program recorded therein, and a recording medium readable in the evening.

Recently, e-mail communication has become commonplace among companies and individuals with the spread of the Internet and intranet. This information transmission by e-mail is realized by an e-mail system that transmits e-mail from a source client to a destination client via a network and a mail server. Here, in the e-mail system, an unnecessary e-mail may be transmitted due to a user's operation error or error. In such a case, the use efficiency of resources such as the network and the memory is reduced, and the user of the receiving side becomes inconvenient. Therefore, there has been a long-felt need for means and methods that can effectively solve such problems. Background art

FIG. 16 is a diagram showing a schematic configuration of a conventional e-mail system. In this figure The e-mail system shown is a client-server communication system that sends e-mail from a source client to a destination client via a mail server.

In this figure, a network 10 is an Internet or an intranet. Clients 20A to 20D are connected to the network 10 as clients, and a mail server 30 is connected as a server. The client 20A transmits e-mails via the network 10 It has an e-mail transmission function of sending e-mail to the mail server 30 and an e-mail acquisition function of downloading e-mail addressed to itself by referring to the mail server 30 via the network 10.

Here, as a protocol for realizing the e-mail transmission function, for example, SMT P (Simple Mail Transfer Protocol) is used. On the other hand, a protocol for realizing the e-mail acquisition function is as follows. For example, POP 3 (Post Office Protocol version 3) is used.

The input unit 21A is a keyboard, a mouse, or the like connected to the client 20A, and is used for inputting a header and a text constituting an e-mail. The header consists of date, address, title, bonbon copy, blind carbon copy, etc. The display unit 22A is a CRT (Cathode-Ray Tube) .LCD (Liquid Crystal Display) or the like connected to the client 20A, and displays an e-mail creation screen and a received e-mail display screen. .

The clients 20B to 20D have the same configuration as the client 20A, and have an e-mail transmission function and an e-mail acquisition function based on SMTP and P0P3. The input unit 21B and the display unit 22B are connected to the client 20B, and the input unit 21C and the display unit 22C are connected to the client 20C. Similarly, an input section 21D and a display section 22D are connected to the client 20D. Here, a unique address is assigned to each of the clients 20A to 20D. The mail server 30 has an e-mail saving function for temporarily saving (accumulating) e-mails transmitted from the clients 20 A to 20 D in a storage unit (not shown). It has a reception notification function of sending a reception notification to the client that is the destination, and an e-mail transmission function of transmitting the evacuated e-mail to the client. Here, the mail server 30 communicates with the transmission source client using SMTP, and communicates with the destination client using POP3.

Next, the operation of the above-described conventional e-mail system will be described with reference to the sequence diagram shown in FIG. Here, the transmission operation of transmitting an e-mail from the client 20A shown in FIG. 16 to the clients 20B to 20D and the transmission of the e-mail from the clients 20B and 20C to the clients 20B to 20D are performed.

The transfer operation for transferring data to 20 D will be described.

First, in the transmission operation, the user of the client 20A shown in FIG. 16 uses the input unit 21A to create e-mail addressed to the clients 20B to 20D, respectively. In this case, it is assumed that the contents of the body of the three e-mails created are the same and only the destination included in the header is different. Also, the title of the three e-mails shall be "About the Terms".

Then, in step S1 shown in FIG. 17, when the created three e-mails are sent from the client 20A to the clients 20B to 20D, respectively, the three e-mails Are received by the mail server 30 via the network 10. As a result, the mail server 30 recognizes the destination from the header of each of the three e-mails, and then temporarily saves the three e-mails in the storage unit (not shown).

Next, in step S2, the mail server 30 issues a reception notification to the clients 20B to 20D, which are destinations, via the network 10. Accordingly, in step S3, the client 20B accesses the mail server 30 via the network 10 and sends the mail 20 to the mail server 30 saved in the storage unit of the mail server 30. Browse e-mail. As a result, information relating to the e-mail is displayed on the display section 22B of the client 20B. This information includes the mail status indicating whether the e-mail has been read, the title, the sender, and the like.

Then, when a download request is issued from the client 20B, the e-mail is downloaded to the client 20B via the network 10. Thus, the e-mail is displayed on the display unit 22B.

Similarly, in step S3, each of the clients 20C and 20D accesses the mail server 30 via the network 10 to refer to the e-mail and then download it. That is, in this case, three e-mails containing the same text sent from client 20A were received by clients 20B to 20D, respectively.

Next, a case where the electronic mail received from the client 20B and the client 20C \ the client 20A is transferred to the client 20D will be described. In this transfer operation, the user of the client 20B creates an (forwarded) e-mail addressed to 20D using the input unit 21B. In this case, the (forwarded) e-mail is created using the e-mail received from Client 2 OA. Therefore, the body of the (forwarded) email is the same as the body of the previously received email. However, in the (forwarding) e-mail header, the destination is client 20D, and the title of the e-mail is "forwarding: terms and conditions". Also, at client 20C, (forwarded) e-mail is created in the same manner as client 20B. Then, in step S1 shown in FIG. 17, when the created (transferred) e-mail is transmitted from the clients 20B and 20C to the client 20D, respectively, two messages are sent. (Transfer) The e-mail is received by the mail server 30 via the network 10. Thus, the mail server 30 recognizes the destination (in this case, the client 20D) from the header of each of the two e-mails, and then stores the two (forwarded) e-mails in the storage unit (not shown). Evacuate temporarily. Next, in step S2, the mail server 30 is connected via the network 10 A reception notification is sent to the client 20 D, which is the destination. Accordingly, in step S3, the client 20D accesses the mail server 30 via the network 10 and sends two (transfer) electronic mails addressed to itself stored in the storage unit of the mail server 30. Browse email. As a result, information relating to the two (forwarded) e-mails is displayed on the display section 22D of the client 20D.

Then, when a download request is issued from the client 20D, the two (forwarded) e-mails are downloaded to the client 20D via the network 10. As a result, two (forwarded) e-mails are displayed on the display unit 22D.

By the way, in the conventional e-mail system, a situation often occurs that an e-mail having the same text is repeatedly transmitted to the same destination due to a transmission operation error or a user error. In this case, useless e-mails are transmitted, and the traffic volume of the network 10 increases in proportion to the number of clients that have repeatedly transmitted e-mails. For this reason, the conventional e-mail system has a problem that network utilization efficiency is reduced.

Further, as described with reference to FIG. 16, when an e-mail having the same text is sent from the client 2 OA to a plurality of destinations (clients 20B to 20D), the In some cases, the received e-mail is forwarded from the clients 20B and 20C to the client 20D.

For example, an e-mail is duplicated from Client 2 OA to Client 20 D, and an e-mail with the same body as the above e-mail is transferred from Client 20 B and Client 20 C to Client 20 D. In this case, the client 20D is notified from the mail server 30 to the client 20D that four convenient electronic mails have been received.

In this case, the display screen shown in FIG. 18 is displayed on the display section 22D of the client 20D. In FIG. 18, “number” is a serial number given to the received e-mail, and “mail state” indicates whether or not the e-mail has been read. Things. “Email title” is the title of the e-mail (for example, “About the rules” and “Transfer: About the rules”), and “Sender” is the sender of the e-mail. Here, in the “sender”, A corresponds to client 20 A, B corresponds to client 20 B, and C corresponds to client 20 C, respectively. Also, in FIG. 18, the e-mails with the “numbers” of “1” and “2” were sent from Client 2 OA, respectively, and the e-mails with the “numbers J” of “3” and “4” were sent. The mail was transferred from Client 20B and Client 20C.

That is, the contents of the four e-mails of “number” and “1” to “4” are the same or substantially the same. Therefore, in this case, the user of the client 20D may read the same e-mail many times, although reading one e-mail is sufficient. Therefore, there was a problem that the usability was very bad.

Further, as described above, when a plurality of e-mails having the same content are transmitted (transferred) to one client, the e-mail is stored in the mail server 30 as separate e-mails. Evacuated to the department. Therefore, in the conventional e-mail system, a useless evacuation area is secured in the storage unit of the mail server 30, so that the memory use efficiency is extremely poor.

The present invention has been made in view of the above, and has been made in consideration of the above circumstances, and has been made in consideration of the above circumstances, an electronic mail system capable of improving network use efficiency, user convenience, and memory use efficiency in a mail server, a client used in the electronic mail system, It is an object of the present invention to provide a computer-readable recording medium in which a mail server and an e-mail program used in a mail system are recorded.

Disclosure of the invention

The present invention relates to a plurality of clients (corresponding to clients 200 A to 200 D according to an embodiment described below) each of which sends and receives an e-mail, and a network ( A mail server connected to the plurality of clients via a network 100 according to an embodiment described later and relaying the electronic mail (to a mail server 300 according to an embodiment described later). The client comprises: an e-mail creating means for creating an e-mail including a body (corresponding to a control unit 203 A to 203 D according to an embodiment described later); A storage unit for storing information about the transmitted e-mail (corresponding to the storage units 205A to 205D of an embodiment described later), and a text that matches the text included in the new e-mail Is stored in the storage means, and control means for stopping transmission of the new e-mail (corresponding to the control units 203A to 203D of an embodiment described later) is provided. The mail server is the client When an e-mail including a text and an identifier assigned to the text is received from the user, a determination means for determining whether or not the identifier matches an identifier associated with a previously received e-mail (see below). If the determination result of the determination means does not match, a reception notification is issued to the client of the destination of the e-mail, while if the determination result matches, A control unit (corresponding to a control unit 301 of an embodiment described later) that does not issue a reception notification to the client of the destination of the electronic mail.

According to the present invention, in the client, when a new e-mail is created by the e-mail creation means, the control means determines whether or not a text that matches the text contained in the new e-mail is stored in the storage means. Is determined. If the results of the determination by the control means do not match, a new e-mail is sent. If the same e-mail as the e-mail is created after the e-mail is sent, the control means determines that the body of the sent e-mail and the body of the newly created e-mail are different. -The sending of new e-mails will be stopped. That is, in this case, duplicate transmission of an e-mail including the same body is avoided. Further, according to the present invention, when the mail server receives the electronic mail from the client, the determination means determines whether or not the identifier included in the electronic mail matches the identifier regarding the electronic mail received in the past. Determine whether or not. This judgment result If they do not match, the control means sends a notification of receipt to the e-mail destination club. On the other hand, if the above determination results match, the control means determines that the same text as the text of the electronic mail has already been notified to the client, and does not issue a reception notification to the client.

As described above, according to the present invention, before transmitting a new e-mail, the client determines whether the text included in the new e-mail matches the text included in the transmitted e-mail. Checking and stopping the transmission of new e-mails when they match, avoiding duplicate transmission of e-mails containing the same body text, improving network utilization efficiency.

Further, according to the present invention, in the mail server, when the identifier of the new e-mail received matches the identifier of the e-mail received in the past, the reception notification is not issued to the client. This eliminates the need to refer to multiple e-mails containing the same text, thus improving the usability of the user.

The present invention also provides a client (e.g., a client 200 according to an embodiment described later) used in an e-mail system that transmits an e-mail via a network (corresponding to a network 100 according to an embodiment described later). (Equivalent to 0 A to 200 D), an e-mail creating means for creating an e-mail including the text (equivalent to a control unit 203 A to 300 D according to an embodiment described later), The storage means for storing the information about the sent e-mail and the text that matches the text included in the new e-mail are stored in the storage means (the storage units 205 A to 200 in an embodiment described later). (Equivalent to 5D), a control means (corresponding to a control unit 203A to 203D according to an embodiment to be described later) for stopping transmission of the new e-mail. It is characterized by the following. According to the present invention, when a new e-mail is created by the e-mail creation means, the control means determines whether or not a text that matches the text contained in the new e-mail is stored in the storage means. Is determined. Then, if the results of the determination by the control means do not match, a new e-mail is sent. Also, an email is sent After that, if an e-mail identical to this e-mail is created, the control means sets a new e-mail because the body of the sent e-mail matches the body of the newly created e-mail. E-mail transmission is stopped. That is, in this case, the duplicate transmission of the e-mail including the same text is avoided.

As described above, according to the present invention, before transmitting a new e-mail, it is checked whether the text included in the new e-mail matches the text included in the transmitted e-mail. In the case of a match, the transmission of a new e-mail is stopped, so that duplicate transmission of e-mails containing the same text can be avoided, and the efficiency of network use is improved.

In addition, the present invention provides a client (e.g., an embodiment described below) for transmitting an e-mail via a network (corresponding to a network 100 according to an embodiment described below). E-mail creation means for creating an e-mail including the body at the client 200 A to 200 D (corresponding to the control unit 203 A to 203 D in an embodiment described later) ), A CRC value calculating means for obtaining a CRC value of the text (corresponding to a control unit 203 A to 203 D in an embodiment described later), and information about the transmitted e-mail and the CRC value. The storage means for storing (corresponding to the storage units 205A to 205D of an embodiment described later) and the CRC value that matches the CRC value of the text included in the new e-mail are stored in the storage means. Remembers and matches the body of the new email When the content is stored in the storage unit, a control unit (corresponding to a control unit 203 A to 203 D according to an embodiment to be described later) for stopping transmission of the new e-mail is used. It is characterized by having. According to the present invention, when a new electronic mail is created by the electronic mail creating means, the CRC value of the body included in the new electronic mail is calculated by the CRC value calculating means. Next, the control means determines whether or not a CRC value that matches the CRC value of the text included in the new e-mail is stored in the storage means. If the result of this determination is inconsistent, a new e-mail is sent. On the other hand, if the judgment result is a coincidence, the control means uses the information included in the new e-mail. It is determined whether or not a text that matches the sentence is stored in the storage unit. If the result of the determination by the control means does not match, a new e-mail is sent.

Further, if the same e-mail is created after the e-mail is sent, the control means sets the CRC value of the text included in the new e-mail and the transmitted e-mail The transmission of the new e-mail is stopped because the CRC value of the included text matches and the text of the sent e-mail matches the text of the newly created e-mail. In other words, in this case, duplicate transmission of an e-mail including the same text is avoided.

As described above, according to the present invention, it is determined whether or not the CRC value of the body included in the e-mail matches before determining whether the body included in the e-mail matches. If the results of the judgment regarding the CRC value do not match, an e-mail can be sent immediately without making a judgment on the text.

Further, the present invention includes a plurality of clients each of which transmits / receives an e-mail, and transmits the e-mail via a network (corresponding to a network 100 of an embodiment described later). In a mail server used in the system (corresponding to a mail server 300 of an embodiment described later), when an e-mail including a text and an identifier assigned to the text is received from the client, the identifier is: If there is a discrepancy between the judgment means (corresponding to the control unit 301 of one embodiment described later) for judging whether or not it matches the identifier of the e-mail received in the past, A reception notification is sent to the client of the e-mail destination. On the other hand, if the judgment result is the same, the client of the e-mail destination is sent to the client. Control means does not emit signals notified; and a (corresponding to the control unit 3 0 1 of the embodiment to be described later).

According to the present invention, when an e-mail from a client is received, the judging means judges whether or not the identifier included in the e-mail matches the identifier of the e-mail received in the past. If the result of this determination is inconsistent, By means, a reception notification is issued to the client of the destination of the electronic mail. On the other hand, if the judgment result is a match, the control means determines that the same text as the text of the electronic mail has already been notified to the client, and does not issue a reception notification to the client.

As described above, according to the present invention, when the identifier of the received new e-mail matches the identifier of the previously received e-mail, the reception notification is not issued to the client. Since there is no need to refer to multiple e-mails containing the same text, the usability of the user is improved. The present invention also provides a mail server used in the above-described electronic mail system, wherein the storage means stores only information on the electronic mail for which the reception notification has been issued by the control means (storage according to an embodiment described later). (Corresponding to part 303).

According to the present invention, the storage means stores only information about the e-mail for which the reception notification has been issued. Conversely, the storage means does not store information about unnecessary e-mails for which no reception notification was issued. Therefore, according to the present invention, unnecessary electronic mail for which no reception notification has been issued is not stored in the storage means, so that the memory use efficiency is improved.

The present invention also provides a computer-readable recording medium recording an e-mail program used for an e-mail system for transmitting an e-mail via a network, wherein the e-mail includes a text. A process, a storage step of storing information on the transmitted e-mail in the storage means (corresponding to step SA11 of an embodiment described later), and a text that matches the text included in the new e-mail. When stored in the storage means, the computer executes a control step (corresponding to step SA5 and step SA7 of an embodiment described later) for stopping transmission of the new e-mail. This is a computer-readable recording medium that stores the e-mail program.

According to the present invention, a new e-mail is created in the e-mail creation step By the control step, it is determined whether or not a body that matches the body included in the new e-mail is stored in the storage unit. Then, if the judgment results in the control process do not match, a new e-mail is sent. If the same e-mail as this e-mail is created after the e-mail is sent, in the control process, the body of the sent e-mail and the body of the newly created e-mail The sending of new e-mails is stopped because of the That is, in this case, duplicate transmission of an e-mail including the same text is avoided.

As described above, according to the present invention, before transmitting a new e-mail, it is checked whether the text included in the new e-mail matches the text included in the transmitted e-mail. In the case of a match, the transmission of the new e-mail is stopped, so that the duplicate transmission of the e-mail including the same text can be avoided, and the use efficiency of the network is improved.

The present invention is also a computer-readable recording medium having a plurality of clients respectively transmitting and receiving e-mails, and recording an e-mail program used for an e-mail system for transmitting the e-mail via a network. When an e-mail including a text and an identifier assigned to the text is received from the client, a determining step of determining whether or not the identifier matches an identifier associated with a previously received e-mail (described later) If the judgment result in the judging step does not match, a notification of reception is sent to the client of the destination of the e-mail, and if the judgment result matches. , Control to not send a notification of receipt to the client of the e-mail This is a computer-readable recording medium in which an e-mail program for causing a process (corresponding to step SB8 of an embodiment described later) to be executed immediately on a computer.

According to the present invention, when an e-mail from a client is received, in the determining step, it is determined whether or not the identifier contained in the e-mail matches the identifier of the e-mail received in the past. If the result of this judgment does not match, In the process, a reception notification is issued to the client of the destination of the e-mail. On the other hand, if the above determination results match, the control step assumes that the same text as the text of the e-mail has already been notified to the client, and does not issue a reception notification to the client.

As described above, according to the present invention, when the identifier of the received new e-mail matches the identifier of the previously received e-mail, the reception notification is not issued to the client. Since there is no need to refer to multiple e-mails containing the same text, the usability of the user is improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a schematic configuration of an embodiment according to the present invention, FIG. 2 is a block diagram showing a configuration of the same embodiment, and FIG. 3 is a diagram shown in FIG. FIG. 4 is a diagram showing resource information in clients 200 A to 200 D, and FIG. 4 shows an example of storage contents in a storage unit 205 A of the client 20 OA shown in FIG. a diagram, FIG. 5 is a diagram showing the data structure of the electronic mail MA ILB ~MA IL _D shown in FIG. 1, FIG. 6, the client 2 0 0 storage of B shown in FIG. 2 FIG. 7 is a diagram showing an example of the contents stored in a unit 205B; FIG. 7 is a diagram showing an example of the contents stored in a storage unit 205C of the client 200C shown in FIG. 2; Mae FIG. 8 is a diagram illustrating a forward e-mail MA IL _AB and MA IL _AC the data structure shown in FIG. 1, FIG. 9 is shown in Figure 2 FIG. 10 is a diagram showing resource information in a server 300; FIG. 10 is a diagram showing an example of storage contents in a storage unit 303 of the mail server 300 shown in FIG. 2; FIG. 11 is a flowchart for explaining the transmission operation in each of the clients 200 A to 200 D shown in FIG. 2. FIG. 12 is a flowchart showing the mail server 300 shown in FIG. FIG. 13 is a flowchart for explaining the transfer operation of each of the clients 200 A to 200 D shown in FIG. 2, and FIG. 14 is a flowchart for explaining the transfer operation. 2 In the display section of the client 200D shown in FIG. FIG. 15 is a diagram showing an example of a display screen. FIG. 15 is a block diagram showing a modified example of one embodiment of the present invention. FIG. 16 is a schematic configuration of a conventional e-mail system. FIG. 17 is a sequence diagram illustrating the operation of the conventional e-mail system. FIG. 18 is a diagram showing the display on the display unit 22D of the client 20D shown in FIG. It is a figure showing an example of a screen. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an embodiment according to the present invention. In this figure, the network 100 is the Internet or Intranet. This network 100 includes clients 200A to 200D and a mail server 3

0 0 is connected.

Client 20 OA sends e-mail to mail server via network 100

—It has an e-mail sending function to send e-mail to the server 300, and an e-mail acquisition function to download e-mail addressed to itself by referring to the e-mail server 300 via the network 100. RU

This client 20 OA realizes an e-mail sending function using SMTP as described above, and also realizes an e-mail acquisition function using POP 3.

. In addition, the client 20 OA has a duplicate transmission prevention function that prevents duplicate transmission of the same e-mail. The details of the duplicate transmission prevention function will be described later.

The input unit 201A is a keyboard, a mouse, or the like connected to the client 20OA, and is used for inputting a header and a body constituting an electronic mail. The header consists of date, address, title, carbon copy, blind carbon copy, etc. The display unit 202A is a CRT, LCD, or the like connected to the client 200A, and displays an e-mail creation screen and a received e-mail display screen.

Clients 200B to 200D have the same configuration as client 200A. It also has an e-mail transmission function based on SMTP and POP 3, an e-mail acquisition function, and a duplicate transmission prevention function.

The input section 201 B and the display section 202 B are connected to the client 200 B, and the input section 201 C and the display section 202 are connected to the client 200 C. C is connected. Similarly, an input unit 201D and a display unit 202D are connected to the client 200D. Where the client 2 0 0 A ~ 2 0 0

D has its own unique address.

The mail server 300 temporarily stores the e-mail transmitted (transferred) from the clients 200 A to 200 D in the same manner as the mail server 300 (see FIG. 16). An e-mail evacuation function that saves (accumulates) the e-mail in 03 (see Fig. 2), a reception notification function that sends a reception notification to the client that is the e-mail destination of the e-mail, and an e-mail that is saved to the client It has an e-mail sending function for sending. Here, the mail server 300 communicates with the sender client using SMTP, and communicates with the destination client using POP3. In addition, the mail server 300 has a duplicate reception notification prevention function for avoiding the reception notification regarding the transferred e-mail substantially the same as the e-mail already notified to the client. The details of the duplicate reception notification prevention function will be described later.

Next, the configuration of the embodiment will be described in detail with reference to FIG. In FIG. 2, parts corresponding to the respective parts in FIG. 1 are given the same reference numerals. In the client 20 OA shown in FIG. 2, the control unit 203 A controls the creation, transmission, and reception of e-mail, and details the operation of the control unit 203 A. Will be described later. The communication unit 204A communicates with the mail server 300 using the above-described SMTP when transmitting an e-mail, and uses POP 3 when e-mail is down. It communicates with the server 300.

The storage unit 205A stores the resource information including the number of transmitted mails SC and the electronic mail configuration information EJ shown in FIG. 3 under the control of the control unit 203A. Sent mail The number SC is the number of e-mails sent from the client 20 OA, and the e-mail composition information EJ is composed of the header information HJ and the text B0 that make up the e-mail to be sent Information.

The header information HJ is composed of the destination TO of the electronic mail, the number of sets ΡΑ, the identifier ID, the CRC value CV, and the body save area pointer BP. The identifier ID is used to uniquely identify the text B〇. The number of pairs PA is the number of pairs of the identifier ID and the body BO in one email. For example, in the case of a newly created e-mail, as shown in Fig. 4, there is one body BO and one identifier ID assigned to it, so the number of sets PA is “1”. It is said.

On the other hand, in the case of a forwarded e-mail created using an e-mail that has already been received, as shown in Fig. 6, in addition to the set of received text and identifier, a new e-mail is added. The set PA is set to “2” because the transfer text created in the above and the identifier assigned thereto exist.

The CRC (Cyclic Redundancy Check) value CV shown in FIG. 3 is, for example, a check code for error detection in an HDLC (High-level Data Link Control) control procedure. Specifically, the CRC value CV is obtained by regarding the body BO as a binary number (message polynomial) consisting of “0” and “1”, and converting the message polynomial into a predetermined generator polynomial (for example, X "is the remainder when divided by ^{^{+ X 12 + X 5 +1)}} . the CRC value CV is a 2-byte data. Text escape area pointer BP is saved in the storage unit 205 a Text It is a pointer to the storage area of B. The body BO is a text data that indicates the contents of the e-mail.

Actually, the information shown in FIG. 4 based on the resource information shown in FIG. 3 is stored in the storage unit 205A. FIG. 4 shows, as an example, the number of transmitted mails SC _A (= 3) corresponding to the three e-mails MA IL _{B to} MA IL _D shown in FIG. 1, and e-mail configuration information EJ _{B to} EJ _d Is illustrated.

Further, the control unit 203A transmits the e-mail configuration information EJ to EJ _D shown in FIG. Based on, create an e-mail MA I LB ~MA IL _D shown in FIG. 5 (a) ~ (c). In addition, these e-mails MA I LB ~! Will be described in detail later VIA IL _D. The interface unit 206A takes an interface between the control unit 203A, the input unit 201A, and the display unit 202A.

The configuration of the clients 200B to 200D is the same as the configuration of the client 200A described above. That is, the client 200 B is composed of a control unit 203 B, a communication unit 204 B, a storage unit 205 B, and an interface unit 206 B, and the client 200 C Control unit 203 C. Communication unit 204 C. Storage unit 205 C and interface unit 206 C. Similarly, the client 200D includes a control unit 203D, a communication unit 204D, a storage unit 205D, and an interface unit 206D.

In the mail server 300, the control unit 301 controls the reception of the e-mail, the notification of the reception to the client, and the control of the download of the e-mail. It will be described later. The communication unit 302 communicates with the clients 200A to 200D using the above-described SMTP when receiving an e-mail, and uses the POP 3 when downloading an e-mail. It communicates with clients 200 A to 200 D.

The storage unit 303 stores the resource information including the management information K and the electronic mail configuration information E J # shown in FIG. 9 under the control of the control unit 301. The management information K is information used for managing e-mail, and is composed of the number of clients CN, the source address S D and the number of held mails S M.

The number of clients CN is the total number of clients to be managed by the mail server 300. In the example shown in FIG. 2, since the mail server 300 manages four clients 200 A to 200 D, the number of clients CN is “4” (see FIG. 10). ).

The sender address SD is the address of the (sender) client that sent the e-mail received by the mail server 300. The number of emails held SM Number of e-mails related to clients. E-mail composition information EJ # is composed of header information HJ # and text B〇 # that constitute the received e-mail. The header information HJ # is composed of a mail hidden MS, the number of sets PA #, an identifier ID #, a CRC value CV #, and a body save area pointer BP #. The mail status MS is an e-mail stored in the mail server 300, which is information indicating whether or not the e-mail was read by the destination client, in other words, whether or not the e-mail was read by the user. is there. The set number PA #, the identifier ID #, and the CRC value CV # correspond to the set number PA, the identifier ID, and the CRC value CV shown in FIG. 3 described above, respectively.

The text save area pointer BP # is a pointer indicating the save area of the text B ## saved in the storage unit 303. The text B〇 # is text data representing the content of the e-mail, and corresponds to the text B〇 shown in FIG. 3 described above.

Actually, the information shown in FIG. 10 based on the resource information shown in FIG. 9 is stored in the storage unit 303. The first 0 Figure, as an example, the management information K corresponding to the electronic mail MA I LB ~MA IL _D of triplicate shown in FIG. 1, the e-mail configuration information EJ # _B ~EJ # _D shown ing.

Next, the operation of the above-described embodiment will be described with reference to the flowcharts shown in FIGS. 11 to 13, respectively. Here, the transmission operation of transmitting one electronic mail MAI LB from client 200A to client 200B shown in FIGS. 1 and 2 and the transmission operation from client 20OA to clients 200B to 200D are described. MAIL _{B to} MA IL. A description will be given of the broadcast transmission operation of transmitting the client 200B and the client 200C, and the transfer operation of transmitting the transfer e-mail MAIL _AB and MAIL _AC to the client 200D. .

First, in the transmission operation, the user of the client 20 OA shown in FIG. 2 uses the input unit 201 A to input information about the e-mail MAIL B addressed to the client 200 _B. Specifically, the user sets “B”, which is the destination of client 200 B, as the destination TO shown in FIG. 3, and the body BO _A shown in FIG. Then, enter “XXXX rules are as follows: ■ · · ·” as shown in the figure.

In this case, the number S C of transmitted mails shown in FIG. 3 is “0”. It is also assumed that no electronic mail composition information is stored in the storage unit 205A.

Then, in step SA1 shown in FIG. 11, the control unit 203A of the client 20OA shown in FIG. 2 uses the text BO _A shown in FIG. After giving 0 0 1, go to step SA2. In step SA2, the control unit 203A calculates the CRC value for the new text BO _A, and then proceeds to step SA3.

Specifically, the control unit 203A regards the text B OA as binary data (message polynomial) consisting of “0” and “1”, and generates this message polynomial in a predetermined manner. polynomial ^{^{(e.g., X 16 + X 12 + X}} 5 + 1) divided by, finding the Retained surplus as the CRC value of the two bytes. In this case, CRC value is assumed to be "0 x 7 6 54" (see FIG. 4 header information HJ _B).

In step SA 3, the control unit 203 _A reads out the number of sent mails SC _A (−0) from the storage unit 205 _A and the e-mail configuration information regarding the sent e-mails, Proceed to. In this case, since no electronic mail configuration information is stored in the storage unit 205A, the control unit 203A reads only the number of transmitted mails SCA (= 0).

In step SA4, the control unit 203A determines whether the CRC value included in the read e-mail configuration information matches the new CRC value (= 0x7654) obtained in step SA2. Judge. In this case, since the e-mail composition information has not been read, the control unit 203A sets the determination result of step SA4 to "No" and proceeds to step SA8.

In step SA8, the control unit 203A decrements the number of transmitted mails (= 0) obtained from the number of transmitted mails S4 by 1, and then proceeds to step SA9. this In this case, the number of sent mails is “1-1”. The number of transmitted mails is a variable used when reading out the electronic mail configuration information from the storage unit 205A.

In step S A9, control unit 203A determines whether or not the number of transmitted mails is “0”. In this case, the number of transmitted e-mails is “1 1”, but as an exception to the initial state, the control unit 203A sets the determination result of step SA9 to “Yes” and proceeds to step S A11.

If the determination result of step SA9 is “No”, the control unit 203A proceeds to step SA10, reads out the e-mail configuration information on the next transmitted mail from the storage unit 205A, Returning to step SA4, the above operation is repeated.

In this case, in step SA11, the control unit 203A secures a save area in the storage unit 205A, and then saves the e-mail configuration information EJB shown in FIG. 4 in this save area. Proceed to SA 12. In this case, to the escape area is e-mail configuration information EJ _b consisting of the header information HJ _B and body BOA is retracted. The header information HJ _B includes the destination (= B), the number of pairs of the identifier and the body (= 1), the identifier (= A00001), the CRC value (= 0x7654), and the body save area void. It consists of evening and evening. Here, the number of pairs of the identifier and the text is “1” because the identifier (= A 000 1) and the main text BOA are one pair.

In step SA 1 2, the control unit 203 A, based on the e-mail configuration information EJ _B shown in FIG. 4, the header H _B and body BO _A Tona Ru email shown in FIG. 5 (a) Create MA I LB.

In the header _Hb of this e-mail MA I LB, the destination (= B), the number of pairs of the identifier and the main text (= 1), the identifier (= A 000 1), and the CRC value (= 0 X 7654) are This is information obtained from the header information HJB shown in Fig. 4. The source address (= A) in the header H _B is the address of the client 200A. Here, when a transmission instruction is issued by the user, the control unit 203A controls the communication unit 204A to transmit the e-mail MAIL _B, and then transmits the e-mail MAIL _B as shown in FIG. The number of transmitted e-mails (in this case, “0”) is incremented by one, and a series of operations ends as “1”.

In step SB1 shown in FIG. 12, the control unit 301 of the mail server 300 determines whether an e-mail transmission request has been received from a client, in other words, whether an e-mail has been received. In this case, the result of the determination is “No” and the same determination is repeated.

Then, when the e-mail MAIL _B (see FIG. 5 (a)) transmitted from the client 200A is received by the communication unit 302 of the mail server 300 via the network 100, the control unit 301 Then, the determination result of step SB1 is set to “Yes”, and the process proceeds to step SB2.

In step SB 2, the control unit 301 acquires the identifier (= A 000 1) and the number of sets (= 1) from the header H _b of the email MA I LB shown in FIG. Proceed to step SB3. In step SB3, the control unit 301 determines whether or not the identifier related to the electronic mail MA ILB (= A0001) matches the identifier related to the electronic mail requested to be transmitted in the past. In this case, the determination result is “No”, and the process proceeds to Step SB4.

In step SB4, the control unit 301 saves the text BOA in the e-mail MAIL _B (see FIG. 5 (a)) as the text BO # _B shown in FIG. Then, proceed to Step SB5. In step SB 5, the control unit 30 1, based on the header H _b in the electronic mail MA IL _B (FIG. 5 (a) refer), creates a header information HJ # _B shown in the first 0 Figure, this Is stored in the storage unit 303, and then the process proceeds to step SB6.

Here, the header information HJ # _B shown in FIG. 10 includes the mail status (two unread), the number of pairs of the identifier and the body (= 1), the identifier (= A 000 1), the CRC value (= 0 X 76 54) and a text save area pointer. This text save area pointer is a pointer indicating the save area of the main text BO # _B.

In step SB6, the control unit 301 sends the header information HJ # _B (= 1) is decremented by 1 to “0”, and then the process proceeds to Step SB7. In step SB7, control unit 301 determines whether or not the number of sets (= 0) is "0". In this case, the determination is "Yes", and the flow proceeds to step SB8.

In step SB8, control unit 301 determines whether or not it is necessary to notify the client that is the destination of the electronic mail of the reception. This criterion is that if the result of the determination in step SB 3 is “Yes”, that is, the identifier of the e-mail requested to be transmitted and the identifier of the e-mail requested to be transmitted in the past are If they do, the result of the determination in step SB 8 is “No”. In this case, since the determination result of step SB3 regarding e-mail MAIL _B is "No", control unit 301 sets the determination result of step SB8 to "Yes", and proceeds to step SB9. In step SB9, the control unit 301 issues a reception notification to the client 200B, which is the destination of the e-mail MAI LB, and ends a series of processing.

As a result, the control unit 203B of the client 200B accesses the mail server 300 via the network 100, and sends the e-mail relating to the e-mail MA I LB stored in the storage unit 303 of the mail server 300 to itself. Refer to the configuration information EJ # _B (see Fig. 10). As a result, information related to the e-mail is displayed on the display unit 202B of the client 200B.

Then, when a down-load request is issued from the control unit 203B of the client 200B, the e-mail MAILB is down-loaded to the client 200B via the network 100. Thereby, electronic mail MAILB is displayed on display section 202B.

Next, after transmitting the above-described e-mail MA I LB to the client 200 _B , the same e-mail as the e-mail MA IL _B (hereinafter, referred to as a duplicate e-mail) is transmitted due to a user operation error or mistake. The following describes the case of duplicate transmission. In this case, the duplicate e-mail transmission is avoided by the duplicate transmission avoidance function of the client 20 OA. That is, regarding the above-mentioned duplicate e-mail, in step SA 1 shown in FIG. 11, the control unit 203 A of the client 20 OA shown in FIG. 2 uses the AO 002 Then, go to step SA2. Here, the text of the duplicate e-mail is the same as the text BO _A shown in FIG.

In step SA2, control unit 203A obtains the CRC value of the body of the duplicate e-mail as "0X7654", and then proceeds to step SA3. In step SA3, the control unit 203A reads from the storage unit 205A the number of transmitted mails SC _A (= 1) and the electronic mail configuration information EJB regarding the transmitted electronic mail MA IL _B, and then reads the step SA Proceed to 4.

In step SA4, the control unit 203A transmits the CRC value (0x7654) included in the read e-mail configuration information EJB (see FIG. 4) and the CRC value (= 0) regarding the duplicate e-mail obtained in step SA2. x 7654) is determined. In this case, control unit 203A sets the determination result of step SA4 to “Yes”, and proceeds to step SA5.

At step SA5, the control unit 203 A comprises a body duplicate e-mail, and a body B_〇 _a of email one Le MA IL _B (see FIG. 4) are compared in character units, whether they are the same Judge. In this case, control unit 203A sets the determination result as “Yes” and proceeds to step SA6. If the determination result of step SA5 is “No”, control unit 203A proceeds to step SA8.

In this case, in step SA6, the control unit 203A determines that the destination (= B) of the transmitted mail (e-mail MAILB) matches the destination (= B) of the newly transmitted mail (duplicate e-mail). Is determined, and in this case, the determination result is “Yes” and the process proceeds to Step SA7. If the result of the determination in step S A6 is “No”, the control section 203A proceeds to step S A8.

In this case, in step SA7, the control unit 203A causes the display unit 202A to display a message indicating that an error has been sent regarding the duplicate Ends a series of processing without sending.

Next, a case where the e-mail MAILB to MAILD is broadcast from the client 20 OA to the clients 200 B to 200 _D will be described. When the three destinations of the clients 200B to 200D are designated when creating the e-mail on the client 200A described above, the control unit 203A performs the same processing as the above-described case of the e-mail MA I LB. Then, the electronic mail composition information EJ _B to EJ _D shown in FIG. 4 are stored in the storage unit 205A. In this case, the destination in the electronic mail configuration information EJ _B is “B”, the destination in the electronic mail configuration information EJ c is “CJ”, and the destination in the electronic mail configuration information EJ _D is “D”.

Each body and identifiers in the e-mail configuration information EJ _B ~EJ _D are both body BO _A and AO 00 1. In the example shown in FIG. 4, the identifiers of the electronic mail configuration information EJB to EJB _D are common, but different identifiers may be added. The number of pairs and the CRC value in the email configuration information EJ _{B to} EJ _D are both “1” and “0x7654”.

When performing the transmission processing, the control unit 203 A, based on the e-mail configuration information EJ _B ~EJ _D shown in FIG. 4, the header H _B and shown in FIG. 5 (a) ~ (c) Create an e-mail MA I LB consisting of the body BOA, an e-mail MA IL _C consisting of the header He and the body BO A, and an e-mail MA IL _D consisting of the header H _D and the body BOA.

When the transmission instruction by the user is issued, the control unit 203 A, by control the communication unit 204 A, after sending the e-mail MA I LB ~MA IL _D, Sent Mail number shown in FIG. 4 SC _{A is set} to “3”.

Then, it is received by the communication unit 302 of the mail server 300 via the client 200 e-mail sent from the A MA I LB ~MA IL _D (FIG. 5 (a) ~ (c) refer) is a network 1 00 Then, the control unit 301 saves the electronic mail configuration information EJ # _{B to} EJ # _D shown in FIG. Here, the email configuration information EJ # _C and EJ # _D are the same as the email configuration information EJ # _B described above, and the email MAIL _C (see FIG. 5 (b)) and the email MAIL _This is the information corresponding to _D (see Fig. 5 (C)). Next, the control unit 3 0 1 issues a reception notification to the client 2 0 0 B to 2 0 0 D is the destination of the e-mail MA I LB ~MA IL _D.

As a result, the control units 203B to 203D of the clients 200B to 200D access the mail server 300 via the network 100, and The e-mail configuration information EJ # B to EJ # _D (see FIG. 10) saved in the storage unit 303 are respectively referred to. Thus, the display unit 2 0 2 B~2 0 2 D client 2 0 0 B~2 0 0 D, information about the e-mail MA IL _B ~MA IL _D are respectively displayed.

Next, the e-mails MA I LB and MA IL _C received from the client 200 OA and the client 200 OA are transferred, and the e-mails MA I LAB (see FIG. 8 (a)) and MA The case of transferring to the client 200D as IL _AC (see FIG. 8 (b)) will be described with reference to the flowchart shown in FIG. Note that the client 200 A and the client 200 D also perform the transfer operation according to the flowchart shown in FIG.

In this transfer operation, the user of the client 200B uses the input unit 201B to create a transfer electronic mail addressed to the client 200D. That is, when the transfer instruction by Interview one The is issued, the control unit 2 0 3 B of the client 2 0 0 B, by using the e-mail MA IL _B of Received shown in FIG. 5 (a), the create an e-mail configuration information EJ _BT shown in FIG. 6, it is retracted it in the storage unit 2 0 5 B. That is, the user of the client 200B uses the input unit 201B to input information about the transfer e-mail MAIL _AB addressed to the client 200D. Specifically, the user is provided with a Ru destination der Client 2 0 0 D "D" as a destination shown in FIG. 6, respectively input a transfer body B_〇 _B shown in Figure 6. in this case, It is assumed that the number of transmitted mails SC _B shown in FIG. 6 is “0”. It is also assumed that no e-mail composition information is stored in the storage unit 205B. Then, in step SC1 shown in FIG. 13, the control unit 203B of the client 200B shown in FIG. 2 assigns an identifier to the transfer text B OB shown in FIG. After assigning B00001, the process proceeds to step SC2. In step SC 2, the control section 2 0 3 B, after asking the CRC value for the transfer body B_〇 _B shown in FIG. 6, the process proceeds to step SC 3. In this case, it is assumed that “ _0x4567 ” (see header information HJ _AB1 ) shown in Fig. 6 has been obtained as the CRC value of the transfer text BOB.

In step SC3, the control unit 203B increments the number of transmitted mails SCB (= 0) shown in FIG. 6 by 1 to “1”, and then proceeds to step SC4. In step SC4, after updating (or adding) the e-mail configuration information in the storage unit 205B, the process proceeds to step SC5.

In this case, the control unit 2 0 3 B adds the e-mail configuration information EJ _BT shown in FIG. 6 in serial憶部20 5 B. This email composition information EJ _BT is header information HJ _AB ! , Transfer body B〇 _B , header information HJ _AB2 and body BOA power. Header information HJ _AB1 is the destination (= D), (at this time, "1") the number of sets of the identifier and the text identifier of the transfer body BOB (= B 0 0 0 1 ), the transfer body B_〇 _B It consists of a CRC value and a text save area pointer. This text save area pointer indicates the save area of the transfer body B_〇 _B.

The header information HJ _AB2, an identifier of the present statement B_〇 _A included in the header H _B as shown in FIG. 5 (a) (= A 0 0 0 1), CRC value of the body BO _A (= 0 x 76 54), and a text save area pointer. The body save area pointer is a pointer indicating the save area of the body B OA.

In step SC5, the control unit 203B increments the number of pairs of the identifier and the text (in this case, “1”) shown in FIG. 6 by 1 to “2”, and then proceeds to step SC6. . That is, in this case, the identifier (= B 0 0 1) and the transfer text BOB The number of pairs is “2”, such as the pair of the identifier (= A 000 1) and the body B〇 _A. In step SC6, the control unit 203B sets the CRC value of the transfer text B OB (

-0 x 45 67) is saved in the area of the CRC value (see header information HJ _AB1 ) shown in Fig. 6, and then the process proceeds to step SC7.

In step SC7, the control unit 203B saves the pointer of the save area of the transfer body B OB to the area of the body save area pointer (see the header information _HJAB1 ) shown in FIG. Proceed to step SC8.

In step SC8, the control unit 203B transmits the e-mail configuration information shown in FIG.

Based on EJ _BT, header H _AB1 shown in Figure 8 (a), creates a transfer body BO B, to consist of header H _AB2 and Text BOA forward e-mail MA IL _AB. In the header HABI of this forwarded e-mail MAI LAB, the destination (= D), the number of pairs of the identifier and the main text (= 2), the identifier (= B 000 1), and the CRC value (= 0 x 45 67)

This is information obtained from the header information HJ _AB > shown in FIG.

The source address ( _2B) in the header H _AB1 is the address of the client 200B. The header H _AB2 shown in FIG. 8 (a) corresponds to the header information HJ _AB2 shown in FIG.

Here, when the transfer instruction is issued by the user, the control unit 203 B

4 By forwarding B, forward the forwarded email MAIL _AB . Then, when the transfer e-mail MAIL _AB (see FIG. 8 (a)) transferred from the client 200B is received by the communication unit 302 of the mail server 300 via the network 100, the control unit 30 In step 1, the determination result of step SB1 shown in FIG. 12 is set to “Yes”, and the process proceeds to step SB2.

In step SB2, the control unit 301 sends the transfer e-mail shown in FIG.

After acquiring the identifier (= B 0 0 1) and the number of sets (= 2) from the header H _AB1 of MA IL _AB , and acquiring the identifier (= A 000 1) from the header H _AB2 , step SB 3 Proceed to.

In step SB 3, the control unit 3 0 1, the identifier of the transfer body B_〇 _B (= B 0 0 0 It is determined whether 1) matches the identifier of the e-mail for which transmission has been requested in the past. In this case, the result of the determination is “No”, and the process proceeds to step SB4.

In step SB4, the control unit 301 saves the transfer text BOB in the transfer e-mail MAIL _AB (see FIG. 8 (a)) in the storage unit 303, and then proceeds to step SB5. In step SB5, the control unit ₃₀₁ creates header information based on the header H _AB1 in the forwarded e-mail MAIL _AB (see FIG. 8 (a)) and saves the header information in the storage unit 303. Proceed to step SB6.

In step SB6, the control unit 301 decrements the number of sets (= 2) by 1 to "1", and then proceeds to step SB7. In step SB7, the control unit 301 determines whether or not the number of sets (= 1) is “0”. In this case, the determination is “No” and the process returns to step SB3.

In step SB3, the control unit 301 determines whether or not the identifier of the text BO _A (= A000 1) matches the identifier of the electronic mail for which transmission has been requested in the past. In this case, in order to have received transmission request e-mail MA I LB ~MA IL _D (FIG. 5 (a) ~ (c) refer), the body BOA regarding these emails MA IL _B ~MAIL _D past The identifier is “A000 1”.

Therefore, in this case, the control unit 301 sets the determination result of step SB3 to “Yes” and proceeds to step SB6. In step SB6, control unit 301 decrements the number of sets (= 1) by 1 to "0", and then proceeds to step SB7. In step SB7, control section 301 determines whether or not the number of sets (= 0) is "0". In this case, the determination result is "Yes", and the flow proceeds to step SB8.

In step SB8, control unit 301 determines whether or not it is necessary to notify the client that is the destination of the electronic mail of the reception. As described above, as a criterion, as described above, when the result of the determination in step SB3 is “Yes”, that is, an identifier relating to an e-mail that has been requested to be forwarded and an identifier relating to an e-mail that has been previously requested to be transmitted If the answer is yes, the result of the determination in step SB 8 is “No”. In this case, since the determination result of step SB 3 regarding the forwarded e-mail MAI LAB is “Yes”, the control unit 301 sets the determination result of step SB 8 to “No” and sends the destination client 200 Ends the series of processes without notifying D of reception.

Next, transfer the e-mail MA IL _AC from the client 200 C to the client

The case of transferring to 200D will be described. In this case, the user of the client 200C creates a transfer e-mail addressed to the client 200D using the input unit 201C. That is, when the transfer instruction by the user is issued, the control unit 203 C clients 200 C, as in the case of a transfer mail MAIL _AB described above, email Received shown in FIG. 5 (b) utilizing the MA I Lc, create an e-mail configuration information EJ _CT shown in FIG. 7, it is retracted it in the storage unit 205 C.

That is, the user of the client 200C uses the input unit 201C to input information about the transfer e-mail MAIL _AC addressed to the client 200D. Specifically, the user inputs “D”, which is the destination of the client 200D, as the destination shown in FIG. 7, and the transfer body BOc shown in FIG. 7, respectively. In this case, Sent Mail number SC _C shown in FIG. 7 is assumed to be "0". It is also assumed that no electronic mail composition information is stored in the storage unit 205C. In step SC 1 shown in the first FIG. 3, the control unit 203 C of the client 200 C shown in FIG. 2, as an identifier to the transfer body B 0 _c shown in FIG. 7, for example, CO 00 1 After that, go to step SC2. In step SC 2, the control unit 203 C, after asking the CRC value for the transfer body BO _c shown in FIG. 7, the flow proceeds to step SC 3. In this case, it is assumed that “0x1234” (see header information HJ _AC1 ) shown in Fig. 7 has been obtained as the CRC value of the transfer body BOc.

In step SC3, control unit 203C increments the number of transmitted mails SC c (= 0) shown in FIG. 7 by 1 to “1”, and then proceeds to step SC4. S In Step SC4, after updating (or adding) the e-mail configuration information in the storage unit 205C, the process proceeds to Step SC5.

In this case, the control unit 203 C adds the e-mail configuration information EJ _CT shown in FIG. 7 in serial憶部205 C. The e-mail configuration information EJ _CT, the header information HJ _AC 1, the transfer body BOC, a header information HJ _AC2 and body B_〇 _A. The header information HJ _AC1 is the destination (= D), the number of pairs of the identifier and the text (at this point, “1”)

, Identifier of transfer body BOc (= C000 1). It consists of CRC value of transfer body BOc and body save area pointer. This text save area pointer is a pointer indicating the save area of the transfer text BOc.

The header information HJ _AC2 is FIG. 5 (b) identifier of the present statement B_〇 _A included in the header He shown in (= A 000 1), CRC value of body BOA (= 0 X 7654)

, And a text save area pointer.

In step SC5, control unit 203C increments the number of pairs of the identifier and the text (in this case, “1”) shown in FIG. 7 by 1 to “2”, and then proceeds to step SC6. That is, in this case, the number of pairs is “2”, such as a pair of the identifier (= C 000 1) and the transfer text B〇 _c and a pair of the identifier (= A 000 1) and the text B〇 _A . In step SC6, the control unit 203C transmits the CRC value of the transfer body BOc (

= 0 x 1 234) in the area of the CRC value (header information HJ _AC1 ) shown in Fig. 7, and then goes to step SC7.

In step SC 7, the control unit 203 C, after the point evening save area of the transfer body BOC, and is retracted in the region of the body save area pointer (see header information HJ _AC1) shown in FIG. 7, step SC 8 Proceed to.

In step S C8, the control unit 203 C executes the e-mail configuration information shown in FIG.

Based on the E JCT, create a forwarded email MAIL _AC consisting of the header H _AC1 , the forwarded body BOc, the header H _AC2 and the body BOA shown in Fig. 8 (b). In the header H _AC1 of this forwarded e-mail MAIL _AC , the destination (== D), the number of pairs of the identifier and the body (= 2), the identifier (= C 0 0 1), the CRC value (= 0 X 1 234) Is the information obtained from the header information HJ _AC1 shown in FIG.

The source address (= C) in the header _HAC1 is the address of the client 200C. The header H _AC2 shown in FIG. 8 (b) corresponds to the header information HJ _AC2 shown in FIG.

Here, when a transfer instruction is issued by the user, the control unit 203C transfers the transfer e-mail MAIL _AC by controlling the communication unit 204C. Then, when the transfer e-mail MA I LAC (see FIG. 8 (b)) transferred from the client 200C is received by the communication unit 302 of the mail server 300 via the network 100, The control unit 301 sets the determination result of step SB1 shown in FIG. 12 to “Yes” and proceeds to step SB2.

In step SB 2, the control unit ₃₀₁ acquires the identifier (= C 000 1) and the number of sets (= 2) from the header H _{ac1 of} the transfer e-mail MA I LAC shown in FIG. After acquiring the identifier (= A0001) from the header H _AC2 , proceed to step SB3.

In step SB3, the control unit 301 transmits the identifier of the transfer text BOc (= C 000

It is determined whether 1) matches the identifier of the e-mail for which transmission has been requested in the past. In this case, the result of the determination is “No”, and the process proceeds to step SB4.

In step SB 4, the control unit 30 1, after retracting the transfer e-mail MA IL _AC (FIG. 8 (b) refer) words himself憶部303 transfer body BOc in, the process proceeds to step SB 5. In step SB5, the control unit ₃₀₁ creates header information based on the header H _AC1 in the forwarded e-mail MAIL _AC (see FIG. 8 (b)) and saves it in the storage unit 303. Proceed to step SB6.

In step SB6, the control unit 301 decrements the number of sets (= 2) by 1 to “1 J” and proceeds to step SB7. In step SB7, the control unit 301 sets the number of sets ( = 1) It is determined whether or not the force is “0”. In this case, the result of the determination is “No” and the process returns to step SB3.

In step SB 3, the control unit 301 sends the identifier of the body BO _A (= A 00 0 1) And the identifier of the e-mail for which transmission has been requested in the past. In this case, since the receiving transmission request e-mail MA IL _B ~MA IL _D (FIG. 5 (a) ~ (c) refer) in the past, body BO A for these email MA IL _B ~MAIL _D Is "A00001".

Therefore, in this case, the control unit 301 sets the determination result of step SB3 to “Yes” and proceeds to step SB6. In step SB6, control section 301 decrements the number of sets (= 1) by 1 to "0", and then proceeds to step SB7. In step SB7, control section 301 determines whether or not the number of sets (= 0) is "0". In this case, the determination result is "Yes", and the flow proceeds to step SB8.

In step SB8, control unit 301 determines whether or not it is necessary to notify the client that is the destination of the electronic mail of the reception. As described above, as a criterion, as described above, when the result of the determination in step SB3 is “Yes”, that is, an identifier relating to an e-mail that has been requested to be forwarded and an identifier relating to an e-mail that has been previously requested to be transmitted If they match, the result of the determination in step SB 8 is “No”.

In this case, since the determination result of step SB 3 relating to the forwarded e-mail MA IL _AC is “Yes”, the control unit 301 sets the determination result of step SB 8 to “No” and sends the client 200 Ends the series of processes without notifying D of reception.

Thus, in one embodiment, the client 20 0 over a period of twice the client 200 D from A shall be applied to any and transmit operation of the electronic mail MA IL _D is performed, the client 20 OA overlapping transmission avoidance function Sends a single email MAIL _D to client 200D. Further, in one embodiment, even if the transfer e-mail MAIL _AB and MA IL _AC are transferred from the clients 200B and 200C to the client 200D, the mail server 30

A value of 0 prevents receipt notifications about these forwarded emails MA I LAB and MA IL _{AC from} being sent to client 200D. In this case, the display unit 2 0 2 D client 2 0 OD, the display screen shown in the first 4 figures relating only email MA IL _D of one-mail that originally required is displayed. In FIG. 14, “number” is a serial number assigned to the email MAIL _D received from the client 20 OA, and “mail status” is whether the email MAIL _D has been read. It shows whether or not. Also, "e-mail title" is a person electronic mail title ( "About Rules"), "sender" is the email one Le MA IL _D sender (two A).

As described above, according to one embodiment, before sending a new e-mail, each of the clients 200 A to 200 D sends the text included in the new e-mail and the transmitted e-mail Checks whether the text contained in the email matches with the text included in the email, and if they match, stops sending new emails, thus avoiding duplicate emails containing the same text. As a result, the use efficiency of the network 100 is improved.

Further, according to one embodiment, in mail server 300, when the identifier of the received new e-mail matches the identifier of the previously received e-mail, the destination client (client 200A Since no notification of receipt is issued to ~ 200D), it is not necessary for the client to refer to multiple e-mails containing the same text, which improves the usability of the user.

Further, according to one embodiment, before the client 200 A to 200 D determine whether or not the body included in the email matches, the CRC value of the body included in the email is Since it is determined whether or not they match, if the result of the determination regarding the CRC value does not match, an e-mail can be sent immediately without making a determination on the text.

In addition, according to one embodiment, the mail server 300 does not store information (text, header information) relating to unnecessary e-mails for which no reception notification was issued in the storage unit 303. , Improve memory utilization efficiency.

The embodiment of the present invention has been described in detail with reference to the drawings. The specific configuration example is not limited to this embodiment, and the present invention includes any design change or the like within a range not departing from the gist of the present invention. For example, in the above-described embodiment, an e-mail program for realizing the functions of the clients 200 A to 200 D or the mail server 300 is shown in FIG. By recording the program on a computer-readable recording medium 500 and reading the e-mail program recorded on the recording medium 500 into the computer 400 shown in FIG. The functions of 200 A to 200 D or the mail server 3000 may be realized.

The computer 400 shown in FIG. 15 includes a CPU 401 for executing the above e-mail program, an input device 402 such as a keyboard and a mouse, and a ROM (Read Only Memory) for storing various data. ) 403, RAM (Random Access Memory) 404 for storing the operation parameters, etc., reading device 405 for reading e-mail programs from recording medium 504, output of display, printer, etc. It is composed of a device 406 and a bus BU for connecting each part of the device.

The CPU 410 reads the e-mail program recorded on the recording medium 500 via the reader 405 and executes the e-mail program to execute the above-described processing. Note that the recording medium 500 includes not only a portable recording medium such as an optical disk, a floppy disk, and a hard disk, but also a transmission medium such as a network that temporarily stores and holds data. Media is also included.

As described above, according to the present invention, before transmitting a new e-mail, the client includes the body included in the new e-mail and the main body included in the transmitted e-mail. Checking whether or not to do so and stopping the sending of new e-mails if they match, avoiding duplicate transmission of e-mails containing the same body text, improving network utilization efficiency It has the effect of doing. Further, according to the present invention, in the mail server, when the identifier of the received new e-mail matches the identifier of the previously received e-mail, Since the receipt notification is not issued to the client, it is not necessary for the client to refer to a plurality of e-mails including the same text, thereby improving the user-friendliness.

Further, according to the present invention, before sending a new e-mail, it is checked whether or not a text included in the new e-mail matches a text included in the sent e-mail, In the case of a match, the transmission of a new e-mail is stopped, so that duplicate transmission of e-mails containing the same text can be avoided, resulting in an effect of improving network utilization efficiency. .

Further, according to the present invention, before judging whether or not the text included in the electronic mail matches, it is determined whether or not the CRC value of the text included in the electronic mail matches. Therefore, when the judgment results regarding the CRC value do not match, the e-mail can be transmitted immediately without making a judgment regarding the text.

Further, according to the present invention, unnecessary e-mails for which no reception notification has been issued are not stored in the storage means, so that there is an effect that memory use efficiency is improved. Industrial applicability

As described above, the e-mail system according to the present invention, the client used in the e-mail system, the mail server used in the e-mail system, and the computer-readable recording medium that records the e-mail program are provided in a network. It is useful for e-mail-based communication services because it can improve the efficiency of use, the use of users, and the efficiency of memory use in mail servers.

Claims

The scope of the claims

1. An e-mail system comprising: a plurality of clients respectively transmitting / receiving e-mail; and a mail server connected to the plurality of clients via a network and relaying the e-mail.

The client,

An email creation means for creating an email including a body,

Storage means for storing information about the sent e-mail;

Control means for stopping the transmission of the new e-mail when a text corresponding to the text contained in the new e-mail is stored in the storage means;

With

The mail server,

When an e-mail including the text and an identifier assigned to the text is received from the client, a determination unit configured to determine whether the identifier matches an identifier related to a previously received e-mail,

If the result of the determination by the determination means does not match, a reception notification is issued to the client of the destination of the e-mail, and if the result of determination is a match, the reception notification is transmitted to the client of the destination of the e-mail. Out, control means,

An e-mail system comprising:

2. Clients used in e-mail systems that transmit e-mails over networks

An email creation means for creating an email including a body,

Storage means for storing information about the sent e-mail;

Control means for stopping transmission of the new e-mail when a text corresponding to the text contained in the new e-mail is stored in the storage means;

A client used for an e-mail system, comprising:

3. In a client used in an e-mail system that transmits e-mail via a network,

An e-mail creating means for creating an e-mail including a body,

CRC value calculating means for calculating the CRC value of the text,

A storage unit for storing the transmitted e-mail and information on the CRC value; a CRC value that matches a CRC value of a body included in the new e-mail; a storage unit for storing the new e-mail; When a text that matches the text included in is stored in the storage unit, the control unit stops transmitting the new e-mail.

A client used for an e-mail system, comprising:

4. An e-mail server used in an e-mail system that includes a plurality of clients that each transmit and receive an e-mail and that transmits the e-mail via a network,

If the determination result of the determination means does not match, a reception notification is issued to the client of the destination of the e-mail, and if the determination result is matching, a reception notification is issued to the client of the destination of the e-mail. None, control means,

A mail server used for an e-mail system characterized by comprising:

5. The mail server used in the electronic mail system according to claim 4, further comprising storage means for storing only information on the electronic mail for which the control unit has received the reception notification.

6. A computer-readable recording medium recording an e-mail program used in an e-mail system for transmitting an e-mail via a network,

An e-mail creation process for creating an e-mail including a body,

A storage step of storing information on the transmitted e-mail in the storage unit, and, if a text body that matches a text included in the new e-mail is stored in the storage unit, the transmission of the new e-mail is stopped. A control step to

A computer-readable recording medium that stores an e-mail program for causing a computer to execute the program.

7. A computer-readable recording medium having an electronic mail program for use in an electronic mail system that includes a plurality of clients each of which sends / receives an electronic mail and transmits the electronic mail via a network. A step of determining whether the identifier matches an identifier relating to a previously received e-mail, when an e-mail including the body and an identifier assigned to the body is received from the client;

If the determination result in the determination step does not match, a reception notification is issued to the client of the destination of the e-mail. On the other hand, if the determination result is matching, the reception notification is not output to the client of the destination of the e-mail. Control process and