JP4421968B2 - Mail server, e-mail delivery method, and program - Google Patents

Description

  The present invention relates to the operation of a server that distributes electronic mail.

  By specifying a destination, electronic mail can be transmitted and received between computers. As a destination designation method, there are a normal destination address designation method using “To”, a method using carbon copy “CC”, and a method using blind carbon copy “BCC”. As a method for efficiently specifying a plurality of destinations, there is a method using a mailing list. The user uses these various methods properly or in combination.

  Further, in addition to writing the contents of a message as a body text in an electronic mail, a file can be attached to the electronic mail. If the attached file is used, a large amount of data can be easily sent as an e-mail.

  FIG. 8 is a diagram showing a conventional mechanism for sending general electronic mail. Referring to FIG. 8, a state in which an electronic mail 95 is sent from Mr. A's computer 91 to Mr. B's computer 94 is shown. At that time, Mr. B is designated as the To destination, and a mailing list is designated as the CC destination.

  Mr. A creates an electronic mail 95 and sends it to the mail server 92 to which he belongs. The mail server 92 is an MTA (Mail Transfer Agent) transfer server. In this e-mail 95, Mr. A's address (a#san@a#corporation.co.jp) is sent as the sender, and Mr. B's address (b#san@b#corporation.co.jp) is sent to To. The mailing list address (group@b#corporation.co.jp) is entered as the CC address. Assume that Mr. B is registered in this mailing list.

  The mail server 92 temporarily stores the e-mail 95 in the mail queue 92A, and then the domain name (b # corporation.co.jp) of the To destination address and the domain name (b # corporation.co.jp) of the CC address. ) To the mail server 93. The mail server 93 is an MDA (Mail Delivery Agent) delivery server having a domain name (b # corporation.co.jp).

  Upon receiving the e-mail 95, the mail server 93 distributes it to Mr. B's mail box 93A based on To's destination address (b#san@b#corporation.co.jp). Further, the mail server 93 determines that the CC address is a mailing list, and distributes it to members registered in the mailing list. Since Mr. B is registered in this mailing list, the e-mail 95 is delivered again to Mr. B's mail box 93A.

  Mr. B is a MUA (Mail User Agent) user. Mr. B's computer 94 reads e-mail 95 from Mr. B's own mail box 93A. At that time, since the e-mail 95 is distributed twice to the mail box 93A, the e-mail 95 is read into the computer 94 twice.

  As described above, by using the mailing list, an electronic mail having the same content may reach the same computer a plurality of times from different routes. In that case, the user needs to read and confirm the same e-mail several times, and the work is complicated. In addition, when a file is attached to an e-mail, the amount of data is large and the amount of memory consumed by the computer is increased, and the time required for receiving the e-mail is also increased. Such duplicate delivery of e-mails with the same content can occur not only by mailing lists but also by using forwarded mails.

In order to solve the adverse effects of duplicate delivery, Patent Document 1 discloses a technique in which a computer that receives an email compares the text of the email and deletes the duplicated email.
Japanese Patent Laid-Open No. 10-222438

  The conventional method as disclosed in Patent Document 1 in which the computer that received the e-mail compares the text does not solve the problem of receiving the same e-mail from the mail server. And it takes time. If there is an attached file, the effect of the time will be significant.

  An object of the present invention is to provide a mail server that can effectively eliminate the adverse effects of duplicate delivery of electronic mail.

In order to achieve the above object, a mail server of the present invention is a mail server that receives an email addressed to a computer having an account and stores it in a mailbox.
A mail receiver for receiving e-mail addressed to the computer;
A comparison unit for determining whether or not an e-mail duplicated with the e-mail received by the mail reception unit is stored in the mailbox;
When the comparison unit determines that an e-mail that overlaps the e-mail received by the mail receiving unit is stored in the mailbox, the one e-mail is converted into a file and converted into the other e-mail. And a storage processing unit for storing in the mailbox.

  In the present invention, when the mail receiving unit of the mail server receives the e-mail, the comparing unit determines whether or not an e-mail matching the received e-mail is stored in the mailbox, and the same e-mail is already mailed. If it is stored in the box, the storage processing unit deletes one e-mail and creates a file, attaches it to the other e-mail, and stores it in the mailbox. In addition, the same content e-mail is not repeatedly read from the mail server to the computer, and the user does not need to confirm the same e-mail repeatedly.

  According to the present invention, there is no need to repeatedly store the same contents in the mailbox from the mail server, and the same contents of the e-mail are not repeatedly read from the mail server to the computer. Therefore, it is possible to effectively eliminate the adverse effects of duplicate delivery of e-mails.

  An embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a mechanism for sending an electronic mail in the present embodiment. Referring to FIG. 1, an electronic mail 15 is sent from Mr. A's computer 11 to Mr. B's computer 14. At that time, Mr. B is designated as the To destination, and a mailing list is designated as the CC destination.

  Mr. A creates an electronic mail 15 and sends it to the mail server 12 to which he belongs. The mail server 12 is an MTA (Mail Transfer Agent) transfer server. In this e-mail 15, Mr. A's address (a#san@a#corporation.co.jp) is sent as the sender, and Mr. B's address (b#san@b#corporation.co.jp) is sent to To. The mailing list address (group@b#corporation.co.jp) is entered as the CC address. Assume that Mr. B is registered in this mailing list.

  The mail server 12 temporarily stores the e-mail 15 in the mail queue 12A, and then the domain name (b # corporation.co.jp) of the To destination address and the domain name (b # corporation.co.jp) of the CC address. ) To the mail server 13.

  The mail server 13 is an MDA (Mail Delivery Agent) delivery server having a domain name (b # corporation.co.jp). In this embodiment, when the mail server 13 repeatedly receives the same e-mail to be delivered to the same mailbox a plurality of times, the mail server 13 deletes one e-mail and the attached file and deletes the deleted e-mail. Is attached to the other e-mail. The reason for attaching the contents of the deleted e-mail to the other e-mail is to notify the destination user that the duplicate e-mail has been deleted, and the notification information indicating that it has been deleted in the body of the other e-mail May be added.

  Since the e-mail 15 transferred with the To address is the same as the e-mail 15 transferred with the CC address, the mail server 13 deletes one and attaches the contents to the other. Store in Mr. B's mailbox 13A.

  Mr. B is a MUA (Mail User Agent) user. Mr. B's computer 14 reads the e-mail 15 from Mr. B's own mail box 13A. Since the same e-mail is not delivered a plurality of times to Mr. B's mailbox 13A, the computer 14 does not read the same e-mail repeatedly. In addition, since the e-mail 15 read from the mail box 13A includes the contents attached by the mail server 13, Mr. B can confirm the contents of the e-mail 15 and confirm the To address and CC. Can be recognized by the address of

  FIG. 2 is a block diagram showing the configuration of the MDA distribution server in this embodiment. Referring to FIG. 2, the mail server 13 includes a mail reception unit 21, a comparison unit 22, a storage processing unit 23, and a mail box 13A.

  The mail receiving unit 21 receives an electronic mail addressed to a computer having an account for itself and sends it to the comparison unit 22.

  The comparing unit 22 compares the e-mail received by the mail receiving unit 21 with the e-mail stored in the mail box 13A, and detects a match of the e-mail.

  FIG. 3 is a diagram showing the structure of an e-mail. Referring to FIG. 3A, the e-mail message 31 has a header portion 32 and a body portion 33. The header portion 32 includes a message ID, transmission date / time, subject, sender address, destination address, and the like. The body part 33 includes a text and an attached file. FIG. 3B shows an example of a specific e-mail message. In the e-mail of FIG. 3B, in the header part 32, the subject (Subject) is “About mailing list”, the sender address (From) is a#san@a#corporation.co.jp, and the To address The address is b#san@b#corporation.co.jp, and the CC address is group@b#corporation.co.jp. In addition to the text, two files of “Attachment 1” and “Attachment 2” are attached to the body portion 33.

  FIG. 4 is a diagram illustrating an example of a state in which electronic mails are compared. As shown in FIG. 4, the comparison unit 22 sequentially compares the e-mail received by the mail receiving unit 21 with the data of each e-mail stored in the mail box 13A. At that time, the comparison unit 22 first compares the message ID of the e-mail with the transmission date and time, and if they match, if there is an attached file, it compares the attached file next.

  There are various ways to compare files.

  As an example of the file comparison method, there is a binary code comparison method for comparing each byte and checking for match / mismatch. If the files to be compared are unconverted, they can be compared character by character. When files are encoded and the encoding conditions are different, the files to be compared may be decoded and compared in the decoded state. Further, when files are encoded and the encoding conditions are the same, they may be compared for each character in the encoded state.

  As another example of the file comparison method, there is a method of comparing calculation results using a generator polynomial. If the files to be compared are in an unconverted state, the generator polynomial is calculated on the files as they are and the obtained results are compared. If the files are encoded and the encoding conditions are different, the files to be compared are decoded, the generator polynomial is calculated in the decoded state, and the obtained results are compared. If the files are encoded and the encoding conditions are the same, the generator polynomial is calculated in the encoded state and the obtained results are compared.

  As another example of the file comparison method, there is a method of comparing file names. Since the file name of the attachment file of the e-mail is displayed as “Content-Disposition: attachment; filename =“ file name ””, it may be compared.

  As another example of the file comparison method, there is a method of comparing the contents of the description of the attached file described in the header. The description of the attached file is displayed as “Content-Description: <Description of file content>”, so it can be compared.

  As a result of the above comparison, if the message ID and the transmission date / time match and if there is an attached file, the comparison unit 22 determines that they are the same e-mail.

  When the comparison unit 22 detects that the email matches, the storage processing unit 23 deletes the attached file of the received email and converts only the content into a file if there is an attached file in the email. It is attached to the e-mail on the side stored in the box 13A. In addition, the storage processing unit 23 adds notification information indicating that a duplicate electronic mail has been deleted or attached to the body of the electronic mail stored in the mail box 13A.

  FIG. 5 is a diagram illustrating an example of a state in which a received electronic mail is attached to an electronic mail stored in a mailbox. Here, it is assumed that the received electronic mail 15 (see FIG. 5A) matches the electronic mail 15 ′ (see FIG. 5B) stored in the mail box 13A. The storage processing unit 23 deletes the attached files (attachment 1 and attachment 2) of the electronic mail 15 (see FIG. 5C), and converts the electronic mail 15 into a file. Then, the storage processing unit 23 attaches the file of the electronic mail 15 to the electronic mail 15 ′ as an attached file (the same mail (attachment)) (see FIG. 5D). Further, the storage processing unit 23 adds notification information (attachment notification message) for displaying that a duplicate electronic mail is attached.

  FIG. 6 is a diagram showing e-mail data to which duplicate e-mails are attached. Referring to FIG. 6, an additional file (“ADD” in FIG. 6) is newly attached to the electronic mail to which the duplicate electronic mail is attached in addition to the originally attached file. In addition, notification information (“attachment: about mailing list” in FIG. 6) is added to an email to which a duplicate email is attached.

  The mail box 13A stores an e-mail addressed to a computer having an account in the mail server 13.

  FIG. 7 is a flowchart showing the operation of the MDA distribution server in this embodiment. Referring to FIG. 7, first, when the mail server 13 receives an e-mail (step 101), the mail server 13 determines whether there is e-mail data not compared with the e-mail in the mail box 13A (step 101). 102).

  If there is no uncompared e-mail data in the mailbox 13A, the mail server 13 stores the received e-mail in the mailbox 13A (step 106), and ends the process.

  If there is uncompared e-mail data in the mailbox 13A, the mail server 13 compares the received e-mail with the uncompared e-mail data (step 103), and determines whether or not they are the same mail. (Step 104). At this time, the mail server 13 determines that the e-mail message ID and the transmission date and time match, and if there is an attached file, the same e-mail message also matches.

  If it is not determined that the electronic mail is the same, the mail server 13 returns to the process of step 102. If it is determined that they are the same e-mail, the mail server 13 converts the received e-mail into a file and attaches it to the e-mail stored in the mail box 13A (step 105).

  As described above, in this embodiment, when the mail receiving unit 21 of the mail server 13 receives an e-mail, the comparing unit 22 determines whether an e-mail that matches the received e-mail is stored in the mail box 13A. If the same e-mail has already been stored in the mailbox 13A, the storage processing unit 23 deletes the e-mail, converts the contents of the e-mail excluding the attached file into a file, and creates a mailbox. Since it is attached to the e-mail stored in 13A, the e-mail and the attached file are not stored in the mail box 13A, and the e-mail having the same content is repeatedly read from the mail server 13 to the computer 14. And there is no need for the user to check the same e-mail repeatedly. , It is possible to effectively eliminate the adverse effect of the e-mail duplicate delivery.

  As described above, according to the present embodiment, since the electronic mail and the attached file are not stored in the mail box 13A, the memory consumption required for storing the electronic mail can be reduced. Further, since the same e-mail is not repeatedly read from the mail server 13 to the computer 14, the time required for receiving the e-mail is reduced. In addition, since the user does not need to repeatedly check the same e-mail, the convenience of the user is improved.

  Note that the function of each unit of the mail server 13 according to the present embodiment can be realized by executing a software program having the processing shown in FIG. 7 by a computer.

It is a figure which shows the mechanism in which the email in this embodiment is sent. It is a block diagram which shows the structure of the MDA delivery server in this embodiment. It is a figure which shows the structure of an email. It is a figure which shows an example of a mode that an electronic mail is compared. It is a figure which shows an example of a mode that the received email is attached to the email stored in the mailbox. It is a figure which shows the data of the email to which the duplicate email was attached. It is a flowchart which shows operation | movement of the MDA delivery server in this embodiment. It is a figure which shows the structure in which the conventional general electronic mail is sent.

Explanation of symbols

11, 14 Computer 12, 13 Mail server 12A, 13A Mailbox 15, 15 'E-mail 21 Mail receiving unit 22 Comparison unit 23 Storage processing unit 31 Message 32 Header unit 33 Body unit 101-106 Steps

Claims (19)

A mail server that receives e-mail addressed to a computer with an account and stores it in a mailbox,
A mail receiver for receiving e-mail addressed to the computer;
A comparison unit for determining whether or not an e-mail duplicated with the e-mail received by the mail reception unit is stored in the mailbox;
When the comparison unit determines that an e-mail that overlaps the e-mail received by the mail receiving unit is stored in the mailbox, the one e-mail is converted into a file and converted into the other e-mail. attached to possess a storage processing unit for storing the mailbox,
In the determination of duplication of e-mail, the comparison unit further compares the file if a file is attached to the e-mail,
In the determination of the comparison unit, when the emails to which the file is not attached are duplicated in the determination of the comparison unit, one of the emails is filed and attached to the other email, and in the determination of the comparison unit When the email attached with the file is duplicated including the attached file, only one of the emails excluding the attached file is converted into a file and attached to the other email.
mail server.   The mail server according to claim 1, wherein the comparison unit compares the message ID and the transmission date / time in determination of duplication of electronic mail. The mail server according to claim 1, wherein the comparison unit checks each byte for matching in the file comparison. The mail server according to claim 1, wherein the comparison unit checks whether the results obtained by performing a predetermined operation on the file are equal in the file comparison. The mail server according to claim 4 , wherein the predetermined operation is an operation using a generator polynomial. The comparison unit, if it is encoded in the file are different encoding conditions to be compared, comparing the file after decoding in each coding conditions, any one of claims 3 to 5 The mail server described in. The mail server according to any one of claims 3 to 5 , wherein the comparison unit compares the files in the encoded state if the files to be compared are encoded under the same encoding condition. . When the comparison unit determines that an e-mail duplicated with the e-mail received by the mail receiving unit is stored in the mailbox, the storage processing unit sets the one e-mail as a file. The mail server according to any one of claims 1 to 7 , wherein when the file is converted, the file attached to the electronic mail is deleted to perform the file conversion. The storage processing unit deletes the one e-mail when the comparing unit determines that an e-mail that overlaps the e-mail received by the mail receiving unit is stored in the mailbox. Or the mail server of any one of Claims 1-8 which adds the notification information which displays that it attached to said other electronic mail. An email delivery method for receiving an email addressed to a computer having an account in a mail server and storing the email in a mailbox for delivering the email,
Receiving an email addressed to the computer;
Determining whether an email duplicated with the received email is stored in the mailbox;
If it is determined that an email that overlaps the received email is stored in the mailbox, one email is filed and attached to the other email and stored in the mailbox; and I have a,
In the determination of duplication of e-mail, if a file is attached to the e-mail, the file is further compared,
In the determination, if the e-mail with no file attached is duplicated, one e-mail is converted into a file and attached to the other e-mail. Is duplicated including the attached file, only one email without the attached file is converted into a file and attached to the other email.
E-mail delivery method. 11. The electronic mail delivery method according to claim 10 , wherein the message ID and the transmission date / time are compared in determination of duplication of electronic mail. The electronic mail delivery method according to claim 10 or 11, wherein in the file comparison, each byte is checked for a match. 12. The e-mail delivery method according to claim 10 or 11 , wherein, in the comparison of the files, a match between results obtained by performing a predetermined operation on the files is checked. 14. The e-mail delivery method according to claim 13 , wherein the predetermined calculation is an operation using a generator polynomial. The e-mail according to any one of claims 12 to 14 , wherein if the files to be compared are encoded under different encoding conditions, the files are compared after being decoded under the respective encoding conditions. Delivery method. The e-mail delivery method according to any one of claims 12 to 14 , wherein if the files to be compared are encoded under the same encoding condition, the files are compared in an encoded state. If it is determined that an email that overlaps the received email is stored in the mailbox, when the one email is filed, the file attached to the email is deleted. The e-mail delivery method according to any one of claims 10 to 16 , wherein the filing is performed. If it is determined that an email that overlaps the received email is stored in the mailbox, notification information indicating that the one email has been deleted or attached is added to the other email The e-mail delivery method according to any one of claims 10 to 17 . The program for making a computer perform each step in the electronic mail delivery method of any one of Claims 10-18 .

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