JP7183845B2 - Mail system, data recovery device, data recovery method, and program - Google Patents

Description

The present invention relates to a mail system, a data restoration device, a data restoration method, and a program for restoring mail deleted from a mailbox.

Japanese Laid-Open Patent Publication No. 2004-100002 discloses a device for searching for mail messages in response to inquiries from client computers. The device of US Pat. No. 5,300,005 comprises a first memory for storing mail messages and a second memory for storing full text indexes of mail messages. The apparatus of Patent Document 1 searches a full-text index in response to an inquiry from a client computer to search for mail messages that satisfy the content of the inquiry.

JP-A-11-015759

According to the apparatus of Patent Document 1, when there is an inquiry from a client computer, mail messages stored in the first storage device can be searched using the full text index stored in the second storage device as a condition. However, the device of Patent Literature 1 cannot restore deleted mail messages from mailboxes.

By implementing a mail archive and backing up all the emails that arrive at your mail server, you can restore deleted emails from your mailbox. However, when mail archiving is applied to an environment with a large amount of mail distribution, large-capacity storage is required to back up mails deleted from mailboxes, increasing server construction costs. In addition, if the retention period of archived mail data is limited, the storage capacity can be reduced, but it becomes impossible to restore deleted mail after the retention period has expired.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems and to provide a data restoration device capable of restoring deleted mail from a mailbox without installing a storage for backing up mail data.

A mail system according to one aspect of the present invention includes a mailbox having a storage area for each user, and a mail transmitting/receiving device that receives mail addressed to a user and stores the received mail addressed to the user in a storage area assigned to the user. a data restoration device that acquires mail received by the mail transmitting/receiving device, and registers a search index that associates at least words contained in the mail addressed to the user with mail information of the mail addressed to the user, with respect to the mail addressed to the user; In preparation, the data restoration device extracts words contained in the mail addressed to the user when acquiring the mail addressed to the user, associates the extracted words with the mail information of the mail addressed to the user, and registers them in the search index. , when the restoration request mail requesting the restoration of the restoration target mail deleted from the mailbox is obtained, the search index is referred to and the word associated with the restoration target mail information and the associated mail information are retrieved. Mail stored in a storage area of a user different from the user who requested the restoration request mail, based on the rate of matching between words associated with the extracted mail information and words associated with the mail to be restored. At least one mail is extracted from the mail, and the extracted mail is restored as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present invention includes a mailbox having a storage area for each user, and a mail transmission/reception device that receives mail addressed to a user and stores the received mail addressed to the user in a storage area assigned to the user. is a data restoration device connected to and obtains mail from the mail transmission/reception device, outputs the normal mail if the obtained mail is normal mail, and if the obtained mail is restoration request mail, restore request A restoration reception unit for extracting mail information contained in mail, a search index storage unit for storing search indexes associated with words contained in normal mail and mail information of normal mail, and normal mail from the restoration reception unit A search index registration unit that associates words contained in the input normal mail with the mail information of the normal mail and registers them in a search index, and a restoration reception unit that inputs the mail information of the restoration request mail, and restores the mail to be restored. extracts the words associated with the email information and the associated email information, and based on the match rate between the words associated with the extracted email information and the words associated with the email to be restored, a request for a restoration request email A search index matching section for extracting at least one mail from mails stored in a storage area of a user different from the original user, and a request for a restoration request mail using the mail extracted by the search index matching section as the mail to be restored. and a mail restoration unit for restoring the original user's storage area.

In the data restoration method of one aspect of the present invention, when a mail addressed to a user who uses a mailbox having a storage area for each user is acquired, a word contained in the mail addressed to the user is extracted, and the extracted word and the mail information of the mail addressed to the user. Extract the words associated with the email information of the email and the associated email information, and based on the matching rate between the words associated with the extracted email information and the words associated with the email to be restored, At least one mail is extracted from the mails stored in the storage area of a user different from the requesting user, and the extracted mail is restored as a restoration object mail in the storage area of the requesting user of the restoration request mail.

A program according to one aspect of the present invention includes a process of extracting words contained in an email addressed to a user when an email addressed to a user using a mailbox having a storage area for each user is acquired, A process of registering a search index that associates the mail information of the mail addressed to the user, and when the restoration request mail requesting restoration of the mail deleted from the mailbox is obtained, the search index is referred to and restored. Based on the process of extracting the words associated with the email information of the target email and the email information associated with it, and the matching rate between the words associated with the extracted email information and the words associated with the email to be restored, restore A process of extracting at least one mail from among mails stored in a storage area of a user different from the user who requested the request mail, and storing the extracted mail as the mail to be restored by the user who requested the restoration request mail. The computer is caused to execute a process of restoring to the area.

According to the present invention, it is possible to provide a data restoration device capable of restoring deleted mail from a mailbox without installing a storage for backing up mail data.

1 is a block diagram showing an overview of the configuration of a mail system according to a first embodiment of the present invention; FIG. 1 is a block diagram showing the configuration of a data restoration device for a mail system according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram showing an example of a restoration request mail received by the data restoration device of the mail system according to the first embodiment of the present invention; 4 is a table showing an example of search index information stored by the data restoration device of the mail system according to the first embodiment of the present invention; FIG. 4 is a conceptual diagram showing an example of comparison of search indexes by the data restoration device of the mail system according to the first embodiment of the present invention; 4 is a flowchart for explaining mail reception processing by the mail system according to the first embodiment of the present invention; 4 is a flowchart for explaining search index registration processing by the data restoration device of the mail system according to the first embodiment of the present invention; 4 is a flowchart for explaining data restoration processing by the data restoration device of the mail system according to the first embodiment of the present invention; FIG. 4 is a diagram showing an example of a deletion list acquisition request mail received by the data restoration device of the mail system according to the first embodiment of the present invention; FIG. 10 is a diagram showing an example of a reply mail that the data restoration device of the mail system according to the first embodiment of the present invention replies to the deletion list reply mail; 1 is a block diagram showing an example hardware configuration of a mail system according to a first embodiment of the present invention; FIG.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, the embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following. In addition, in all the drawings used for the following description of the embodiments, the same symbols are attached to the same portions unless there is a particular reason. Further, in the following embodiments, repeated descriptions of similar configurations and operations may be omitted. Also, the directions of the arrows in the drawings are only examples, and do not limit the directions of signals between blocks.
(First embodiment)
First, a mail system according to a first embodiment of the present invention will be described with reference to the drawings. The mail system of this embodiment utilizes the characteristic that electronic mail (hereinafter referred to as mail) is often delivered to multiple destinations. The mail system of this embodiment retrieves mail data deleted from a certain user's mailbox by searching other users' mailboxes.

FIG. 1 is a block diagram showing the configuration of a mail system 1 of this embodiment. As shown in FIG. 1, the mail system 1 includes a mail transmission/reception device 11, a mailbox 12, and a data restoration device 13. FIG. An example in which the mail system 1 is configured as a mail server on the mail receiving side will be described below.

The mail transmitting/receiving device 11 transmits/receives mail using the SMTP (Simple Mail Transfer Protocol) protocol. The mail transmitting/receiving device 11 connects an external mail server 100 and at least one terminal (terminal 10A) used by users (user A, user B, . . . ) using the mail system 1 via a network (not shown). , terminal 10B, . . . ). In FIG. 1, a terminal used by user A is denoted by a terminal 10A, a terminal used by user B is denoted by a terminal 10B, and so on. Hereinafter, when the terminal is not distinguished for each user, the alphabet at the end is omitted and the term "terminal 10" is used.

The external mail server 100 is an external mail server that transmits and receives mail using the SMTP protocol. The external mail server 100 mediates transmission and reception of mail between users who use the mail system 1 and users who do not use the mail system 1 . It should be noted that the external mail server 100 is not included in the configuration of the mail system 1, and its form is not particularly limited as long as it can send and receive mail to and from the mail system 1. FIG.

The terminal 10 is a terminal device such as a computer or a mobile terminal used by a user who uses the mail system 1 . The terminal 10 accesses the mail system 1 using the mailer installed in the terminal 10 itself. A mailer is an application for sending and receiving mails using protocols such as SMTP, IMAP (Internet Message Access Protocol), and POP (Post Office Protocol). The terminal 10 may be configured with a dedicated device for each user, or may be configured so that the same device is shared by a plurality of users. Note that the terminal 10 is not included in the configuration of the mail system 1, and there is no particular limitation as long as it can send and receive mail to and from the mail system 1. FIG.

The mail transmitting/receiving device 11 receives mail from the external mail server 100 or the terminal 10 . The mail transmitting/receiving device 11 delivers the received mail to the mailbox 12 when receiving the mail. At this time, the mail transmitting/receiving device 11 stores the mail in the storage area assigned to the user to whom the received mail is addressed.

When the mail transmitting/receiving device 11 stores the transmitted mail in the mail box 12, the mail can be referred to when the terminal 10 of the user included in the destination of the mail accesses the mail box 12.例文帳に追加For example, when an email is sent, the email sending/receiving device 11 notifies the terminal 10 of the user included in the destination of the email that the email has been sent. Further, for example, when mail is transmitted, the mail transmitting/receiving device 11 stores the mail in the mailbox 12 and transmits the mail to the users included in the destination of the mail.

Also, the mail transmitting/receiving device 11 receives a restoration request mail from the terminal 10 of the user using the mail system 1 . The restore request mail includes mail information of the restore target mail (also called restore target mail). Upon receiving the restoration request mail, the mail transmission/reception device 11 delivers the received restoration request mail to the data restoration device 13 . For example, it is possible to prepare a dedicated mail address for receiving a restoration request mail, and transfer mail sent to that address from the mail transmitting/receiving device 11 to the data restoration device 13 as a restoration request mail. Changing the delivery destination of the restoration request mail can be realized by a mail forwarding function provided in general mailers. If the mail delivery destination is controlled using a general mail delivery control function, the mail transmission/reception device 11 may be omitted from the configuration of the mail system 1 .

The mailbox 12 is a storage area in which mail data (also referred to as mail data) for each user using the mail system 1 is stored. The mailbox 12 has multiple storage areas assigned to each user. Mail for each user is stored in each storage area of the mailbox 12 . The mail stored in the mailbox 12 can be referred to/acquired from the terminal 10 using protocols such as IMAP (Internet Message Access Protocol) and POP. Also, the mail stored in each user area assigned to each user is retrieved in response to access from the data restoration device 13 . The mailbox 12 is a general storage device, and its form is not particularly limited as long as the data restoration device 13 can access it. The mailbox 12 may be omitted from the configuration of the mail system 1 in the same manner as the mail transmitting/receiving device 11 .

The data restoration device 13 acquires mail from the mail transmission/reception device 11 . The data restoration device 13 performs different processes depending on whether the obtained mail is a normal mail (also referred to as a normal mail) that is not a restoration request mail or a restoration request mail.

The data restoration device 13 executes a search index registration process when the normal mail is acquired. In the search index registration process, the data restoration device 13 searches and stores the words included in the header and text of the acquired mail. Even if a certain user deletes the mail from the mailbox 12, the data restoration device 13 leaves the search index of the mail without deleting it.

A search index associates a word extracted from a mail with mail information of the mail from which the word was extracted. It is preferable that the search index be grouped for each user ID of the user who uses the mail system 1 . An example in which a mail ID (Identifier) is used as mail information for uniquely identifying a mail will be described below. If the mail can be uniquely specified using information other than the mail ID, information other than the mail ID may be used as the mail information. In addition to words and mail IDs, the search index may be associated with positions where the words appear (also referred to as appearance positions). Word appearance positions include Subject, Body, Message-Id, and the like. The search index stored by the data restoration device 13 may include data other than words, mail IDs, and appearance positions.

Upon receiving the restoration request mail, the data restoration device 13 executes data restoration processing. In the data restoration process, the data restoration device 13 refers to the search index, searches for words associated with the mail ID of the restoration target mail, and extracts hit words (also referred to as appearing words). After extracting the appearing word, the data restoration device 13 refers to the search index and extracts the mail ID associated with the appearing word. At this stage, the mail with the mail ID extracted by the data restoration device 13 is called a restoration candidate mail.

The data restoration device 13 compares the set of words appearing associated with the restoration candidate email with the set of words appearing in the email to be restored, and restores data based on the matching rate of the words included in the set of words appearing. Extract target emails. For example, when the set of words appearing in the restoration candidate email matches the set of words appearing in the email to be restored, the data restoration device 13 detects the restoration candidate email as the email to be restored. Also, for example, the data restoration device 13 extracts, as the restoration target email, the restoration candidate email having the highest rate of matching with the word appearing in the restoration target email.

The data restoration device 13 acquires from the mailbox 12 the mail extracted as the restoration target mail. The data restoration device 13 copies the mail acquired from the mailbox 12 as the mail to be restored to the storage area of the user who requested the restoration.

For example, when the data restoration device 13 copies the mail extracted as the restoration target mail to the storage area of the restoration requesting user, the data restoration device 13 notifies the terminal 10 of the restoration requesting user via the mail transmitting/receiving device 11 that the restoration is completed. to notify you. The user using the terminal 10 that has received the restoration completion notification can refer to the restoration target mail by accessing the mailbox 12 .

The outline of the configuration of the mail system 1 has been described above. The configuration of the mail system 1 in FIG. 1 is an example, and the configuration of the mail system 1 of this embodiment is not limited to the form as it is.

[Data restoration device]
Next, a detailed configuration of the data restoration device 13 will be described with reference to the drawings. FIG. 2 is a block diagram for explaining the detailed configuration of the data restoration device 13. As shown in FIG. As shown in FIG. 2 , the data restoration device 13 has a restoration reception section 131 , a search index registration section 132 , a search index storage section 133 , a search index collation section 134 and a mail restoration section 135 .

The restoration receiving unit 131 acquires mail from the mail transmitting/receiving device 11 . The restoration receiving unit 131 changes the output destination depending on whether the obtained mail is a normal mail or a restoration request mail. If the received mail is a normal mail, the restoration accepting unit 131 outputs the mail to the search index registration unit 132 . On the other hand, when the received mail is a restoration request mail, the restoration receiving unit 131 extracts the mail information of the restoration target mail from the mail. After extracting the mail information of the mail to be restored, the restoration accepting unit 131 outputs the mail information to the search index matching unit 134 . Note that the restoration receiving unit 131 may be configured to receive a restoration request from a WEB (World Wide Web) page for receiving a restoration request instead of an e-mail.

FIG. 3 is an example of the restoration request mail (restoration request mail 111) acquired by the restoration reception unit 131. As shown in FIG. The restoration request mail 111 in FIG. 3 is sent from the user A, who is the source (From), to the data restoration device 13, which is the destination (To). In the example of FIG. 3, the subject of the restoration request mail 111 is described as "mail restoration request". In the body of the restoration request mail 111, the mail information to be restored is described. FIG. 3 shows an example in which a mail ID (A-000001) is used as mail information.

The search index registration unit 132 acquires the mail from the restoration reception unit 131 . The mails acquired by the search index registration unit 132 are normal mails. The search index registration unit 132 analyzes the content of the acquired mail and extracts the destination address and words contained in the text of the mail. The search index registration unit 132 associates the extracted word with the mail ID and registers it in the search index of the search index storage unit 133 .

A search index associates a word extracted from a mail with the mail ID of the mail in which the word appears. For example, words that appear in the text, Message-Id header, To header, Subject header, etc. are registered in the search index stored in the search index storage unit 133 . The search index is preferably associated with the user ID of the user using the mail system 1. FIG. Note that the search index information may be associated with a word appearing in the mail and the position where the word appears.

The search index storage unit 133 is a storage unit that stores search indexes. The search index of the search index storage unit 133 is registered by the search index registration unit 132 in association with the word extracted from the mail and the mail ID of the mail in which the word appears. The search index storage unit 133 stores search indexes of mails sent to users using the mail system 1 . The information registered in the search index stored in the search index storage unit 133 is kept as it is even if the mail stored in the mailbox 12 is deleted.

FIG. 4 is a search index table 120 in which search indexes stored in the search index storage unit 133 are summarized. In the search index table 120 of FIG. 4, the words extracted from the mail, the position where the word appears, and the mail ID of the mail in which the word appears are summarized for each user ID of the user who uses the mail system 1. It is The search index table 120 may contain information other than the data shown in FIG.

The search index matching unit 134 acquires the mail ID of the mail to be restored from the restoration receiving unit 131 . Upon acquiring the mail ID of the mail to be restored, the search index matching unit 134 searches for words associated with the mail ID from the search index stored in the search index storage unit 133 . The search index matching unit 134 extracts words hit by the search.

Search index matching unit 134 searches the search index stored in search index storage unit 133 for a mail ID associated with the extracted word. Then, the search index matching unit 134 compares the set of words associated with the mail ID hit by the search with the set of words associated with the mail ID of the mail to be restored.

The search index matching unit 134 detects, as restoration target emails, emails that have a high matching rate with words included in a set of words associated with the email ID of the restoration target emails, and stores the email IDs of the detected emails in the email restoration unit. Send to 135. Note that the search index matching unit 134 may detect a mail to be restored in which all the words included in the set of words associated with the mail ID of the mail to be restored match. may be detected as the mail to be restored.

FIG. 5 is an example of comparing words appearing in order to restore the mail with the mail ID A-000001 based on the search index stored in the search index table 120 of FIG. In the following, each mail is distinguished by mail ID and described. For example, a mail with a mail ID of A-000001 is described as A-000001.

In A-000001, words such as ``regular meeting'', ``care'', ``always'', ``September 27th'', ``Mrs. A word that appears in A-000001 also appears in A-000008, B-0000092, and so on. For example, it is assumed that the matching rate between the word appearing in A-000001 and the word appearing in A-000008 is 60%. It is also assumed that the matching rate between the word appearing in A-000001 and the word appearing in B-000092 is 100%. In this case, the search index matching unit 134 detects that B-000092 with the highest matching rate is the mail to be restored.

The search index matching unit 134 may perform a search using the appearance position of the word in addition to the word. If a search is performed using words whose appearance positions match, the search target words can be narrowed down, thereby reducing the search load and search time.

For example, mails that are stored in storage areas of different users in the mailbox 12 and have matching Message-Id words are mails sent to a plurality of users and stored in storage areas for each user. In other words, a mail stored in a storage area of a different user in the mailbox 12 and having a matching Message-Id is a mail to be restored.

If there is no mail matching the word of Message-Id, the mail to be restored can be detected based on the matching rate of words appearing at other appearing positions. For example, when the same word is included in the mail header such as Subject, there is a high possibility that the mails are the same mail, so the match rate is evaluated as high.

Further, the search range of the search index matching unit 134 may be all users or may be limited to specific users. Since the same mail exists in the storage area of the user included in the addressee of the restore target mail, only the users included in the addressee of the restore target mail may be set as the search range. By narrowing down the search range of the search index matching unit 134 to the users included in the destination of the restoration target mail, the search load and search time for the restoration target mail can be reduced.

The mail system of this embodiment restores mail similar to the restore target mail to the mailbox. Since the configuration of the mail system of this embodiment is the same as that of the first embodiment, the drawings are omitted and the same reference numerals as those of the first embodiment are used for explanation.

Further, the search index matching unit 134 may restore mail (also referred to as similar mail) whose word matching rate exceeds a predetermined threshold although it is not the same as the mail to be restored. For example, when a similar email quotes an email to be restored, the location quoted by the similar email may include the email to be restored. Further, for example, when a restoration target email quotes a similar email, there is a possibility that the text of the restoration target email that the user wants to refer to is written in the text of the similar email. In this case, the search index matching unit 134 may restore multiple similar emails.

The mail restoration unit 135 acquires the mail ID from the search index matching unit 134 . The mail restoration unit 135 copies the mail with the mail ID acquired from the search index matching unit 134 to the storage area of the user who requested the restoration request mail. As a result, the restoration target mail is restored in the storage area of the user who requested the restoration request mail. For example, the mail restoration unit 135 can be configured to retrieve from the mailbox 12 the mail assigned the mail ID obtained from the search index matching unit 134 and then store the mail in the mailbox 12 .

The above is the description of the configuration of the mail system 1 of the present embodiment. The configuration of the mail system 1 described above is an example, and the configuration of the mail system 1 of the present embodiment is not limited to the form as it is.

(motion)
Next, the operation of the mail system 1 will be described with reference to the drawings. In the following, mail reception processing by the mail system 1, search index registration processing and data restoration processing by the data restoration device 13 included in the mail system 1 will be explained separately.

[Email reception processing]
First, the mail receiving process executed when the mail system 1 receives mail will be described with reference to the drawings. FIG. 6 is a flowchart for explaining the mail reception process executed by the mail system 1. As shown in FIG.

In FIG. 6, first, the mail system 1 receives mail from the external mail server 100 or one of the terminals 10 (step S11).

Next, the mail system 1 determines whether or not the received mail is a restoration request mail (step S12).

If the received mail is not the restoration request mail (No in step S12), the mail system 1 stores the mail in the storage area of the user to whom the received mail was sent (step S13).

Next, the mail system 1 executes search index registration processing for the received mail (step S14).

On the other hand, if the received mail is a restoration request mail (Yes in step S12), the mail system 1 executes data restoration processing for the received mail (step S15).

The above is the description of the mail reception process of the mail system 1 . The mail receiving process by the mail system 1 according to the flowchart of FIG. 6 is an example, and the mail receiving process by the mail system 1 of this embodiment is not limited.

[Search index registration process]
Next, the search index registration process executed by the data restoration device 13 when the mail received by the mail system 1 is a regular mail will be described with reference to the drawings. FIG. 7 is a flowchart for explaining the search index registration process executed by the data restoration device 13. As shown in FIG.

In FIG. 7, first, the data restoration device 13 extracts words contained in the obtained mail (step S121). For example, the data restoration device 13 extracts words appearing in the text, Message-Id header, To header, Subject header, etc. from the acquired mail.

Next, the data restoration device 13 associates the extracted word with the mail information and registers it in the search index (step S122). For example, the data restoration device 13 uses a mail ID as mail information for uniquely identifying a restoration target mail. For example, the data restoration device 13 may register the extracted word in the search index in association with the appearance position of the word or the user ID of the destination of the mail.

The above is the description of the search index registration process executed by the data restoration device 13 . The search index registration processing by the data restoration device 13 according to the flowchart of FIG. 7 is an example, and does not limit the search index registration processing by the data restoration device 13 of this embodiment.

[Data restoration process]
FIG. 8 is a flowchart for explaining data restoration processing performed by the data restoration device 13 when the mail received by the mail system 1 is not a restoration request mail.

In FIG. 8, first, the data restoration device 13 extracts the mail information of the restoration target mail from the restoration request mail (step S141). For example, the data restoration device 13 uses a mail ID as mail information for uniquely identifying a restoration target mail.

Next, the data restoration device 13 uses the search index stored in the search index storage unit 133 to search for words associated with the mail information of the restoration target mail (step S142). For example, with regard to the mail ID of the mail to be restored, the data restoration device 13 extracts from the search index storage unit 133 a set of words included in the header and text of the mail with that mail ID as words.

Next, the data restoration device 13 extracts words (appearing words) hit by the search (step S143). For example, the data restoration device 13 extracts a set of multiple appearing words hit by the search.

Next, the data restoration device 13 uses the search index stored in the search index storage unit 133 to search for user information associated with the extracted word (step S144).

Next, the data restoration device 13 extracts the user information hit by the search (step S145). The mails extracted at this time are restoration candidate mails.

Next, the data restoration device 13 compares the words extracted based on the restoration target email with the words extracted based on the restoration candidate emails, and extracts at least one of the restoration candidate emails based on the matching rate of the words. one is extracted (step S146). For example, the data restoration device 13 extracts restoration candidate mails whose words all match. For example, the data restoration device 13 extracts the restoration candidate mail with the highest word match rate.

Note that the data restoration device 13 may give priority to searching for an email associated with the destination of the restoration target email. For example, if a mailing list is included in the destination, the data restoration device 13 may expand the address of the mailing list and give priority to searching for mail associated with the destination included in the expanded address.

For example, if a mail with a matching Message-Id value is hit in step S146, the data restoration device 13 may extract the mail with a matching Message-Id value as a restoration target mail. If the Message-Id values do not match, the data restoration device 13 may extract the mail based on the matching rate of words as in step S146.

Then, the data restoration device 13 copies the extracted restoration candidate mail as a restoration target mail to the storage area of the requesting user (step S147).

The above is the description of the data restoration process executed by the data restoration device 13 . The data restoration processing by the data restoration device 13 according to the flowchart of FIG. 8 is an example, and the data restoration processing by the data restoration device 13 of this embodiment is not limited.

[Deletion list request]
Here, an example of a method of responding to a user with a list of deleted mails (also called a list of deleted mails) in response to a user's request will be described. In the following description of the request and return of the list of deleted mails, the data restoration device 13 will be described as the subject of the operation.

Upon receiving a mail requesting a list of deleted mails (also called a list of deleted mails) from the terminal 10 used by any user, the mail transmitting/receiving device 11 outputs the request for a list of deleted mails to the data restoration device 13 .

When the data restoration device 13 acquires a deleted mail list request from the mail transmitting/receiving device 11, it creates a deleted mail list corresponding to the request. For example, the mail transmitting/receiving device 11 uses IMAP log information to extract deleted mails, and creates a list of data including mail IDs, subjects, and dates of deletion of deleted mails as a list of deleted mails. . The data restoration device 13 outputs the created deleted mail list to the mail transmitting/receiving device 11 .

After obtaining the deleted mail list from the data restoration device 13, the mail transmitting/receiving device 11 transmits a mail including the deleted mail list (also called a deleted mail list response) to the requesting terminal 10. FIG.

FIG. 9 is an example of a deleted mail list request (deleted mail list request 112) received by the data restoration device 13. As shown in FIG. The deleted mail list request 112 in FIG. 9 is transmitted from the user A who is the source (From) to the data restoration device 13 which is the destination (To). In the example of FIG. 9, the subject of the deleted email list request 112 is described as "deleted email list acquisition request".

FIG. 10 is an example of a deletion list response mail (deletion list response mail 113) in which the deletion list created by the data restoration device 13 is included in the text. The deletion list response mail 113 in FIG. 10 is sent from the data restoration device 13 as the source (From) to the user A as the destination (To). In the example of FIG. 10, the subject of the deletion list response mail 113 is described as "Re: Mail deletion list acquisition request". In the text of the deletion list response mail 113, the mail ID, Subject, and Date values of the deleted mail are described in a list format.

The above is the description of the method of responding to the user with the list of deleted mails in response to the user's request. For example, a user using a terminal that has received a deleted email list response can refer to the deleted email list included in the received deleted email list response and select an email to be restored.

As described above, the mail system of this embodiment includes a mailbox, a mail transmission/reception device, and a data restoration device. A mailbox has a storage area for each user. A mail transmitting/receiving device receives a mail addressed to a user and stores the received mail addressed to the user in a storage area assigned to the user. The data restoration device acquires the mail received by the mail transmitting/receiving device, and registers a search index for at least associating words included in the mail addressed to the user and mail information of the mail addressed to the user with respect to the mail addressed to the user.

When acquiring a mail addressed to a user, the data restoration device extracts words contained in the mail addressed to the user, associates the extracted words with mail information of the mail addressed to the user, and registers them in a search index.

When the data restoration device obtains a restoration request mail requesting restoration of a restoration-targeted email that has been deleted from a mailbox, the data restoration device refers to the search index and associates words associated with the email information of the restoration-targeted email. extract the email information The data restoration device stores data in a storage area of a user different from the user who requested the restoration request mail, based on the rate of matching between the words associated with the extracted mail information and the words associated with the restoration target mail. extract at least one e-mail from among the e-mails The data restoration device restores the extracted mail as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present embodiment extracts words and positions of appearance of the words included in the mail addressed to the user when the mail addressed to the user is acquired from the mail transmitting/receiving device. The data restoration device associates the extracted word and the mail information of the mail addressed to the user with the appearance position of the word and registers them in the search index. When the data restoration device acquires the restoration request mail, it refers to the search index and extracts the mail information in which the appearance position of the word matches among the words associated with the restoration target mail. The data restoration device stores data in a storage area of a user different from the user who requested the restoration request mail, based on the rate of matching between the words associated with the extracted mail information and the words associated with the restoration target mail. extract at least one e-mail from among the e-mails The data restoration device restores the extracted mail as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present embodiment registers a search index including Message-Id as a word appearance position. When the data restoration device acquires the restoration request mail, the data restoration device refers to the search index and finds Message- Extract emails that match the word associated with the Id. The data restoration device restores the extracted mail as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present embodiment refers to a search index when obtaining a restoration request mail, and extracts mail information associated with words associated with the restoration target mail. The data restoration device stores emails in which the words associated with the extracted email information completely match the words associated with the email to be restored in a storage area of a user different from the user who requested the restoration request email. extracted from the e-mail. The data restoration device restores the extracted mail as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present embodiment refers to a search index when obtaining a restoration request mail, and extracts mail information associated with words associated with the restoration target mail. The data restoration device stores the email with the maximum matching rate between the word associated with the extracted email information and the word associated with the email to be restored in a storage area of a user different from the user who requested the restoration request email. Extract from stored emails. The data restoration device restores the extracted mail as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present embodiment refers to a search index when obtaining a restoration request mail, and extracts mail information associated with words associated with the restoration target mail. The data restoration device restores an email whose matching rate between words associated with the extracted email information and words associated with the email to be restored exceeds a predetermined threshold value by a user other than the user who requested the restoration request email. Extract from mails stored in the storage area. The data restoration device restores the extracted mail as a restoration target mail in the storage area of the user who requested the restoration request mail.

A data restoration device according to one aspect of the present embodiment, when receiving a deleted mail list request from a mail transmitting/receiving device, creates a deleted mail list response including a list of deleted mails in response to the deleted mail list request, and deletes the created deleted mail. Output the list response to the mail sending/receiving device.

A data restoration apparatus according to one aspect of the present embodiment includes a mailbox having a storage area for each user, and mail transmission/reception that receives mail addressed to a user and stores the received mail addressed to the user in a storage area assigned to the user. connected to the device. The data restoration device includes a restoration acceptance section, a search index storage section, a search index registration section, a search index collation section, and a mail restoration section. The restoration reception unit obtains mail from the mail transmission/reception device, outputs the normal mail if the obtained mail is a normal mail, and outputs the mail information contained in the restoration request mail if the obtained mail is a restoration request mail. Extract. The search index storage unit stores a search index in which words included in normal mails are associated with mail information of the normal mails. The search index registration unit receives the normal mail from the restoration reception unit, associates the words contained in the input normal mail with the mail information of the normal mail, and registers them in the search index. The search index matching unit receives the mail information of the restoration request mail from the restoration reception unit, and extracts the mail information associated with the word associated with the mail information of the restoration target mail. The search index matching unit stores the word in a storage area of a user different from the user who requested the restoration request mail, based on the rate of matching between the words associated with the extracted mail information and the words associated with the restoration target mail. Extract at least one email out of the received emails. The mail restoring unit restores the mail extracted by the search index matching unit as the mail to be restored in the storage area of the user who requested the restoration request mail.

The mail system of this embodiment utilizes the characteristic that mail is often delivered to multiple destinations. The mail system of the present embodiment, when receiving mail, indexes words included in the header and text of the mail, and holds the index. The message header information held by the mail system of this embodiment includes information such as a Message-Id header value that uniquely identifies a mail and a To header that indicates the destination of the mail.

The mail system of this embodiment accepts a request to restore mail deleted from a mailbox. When receiving a request to restore deleted mail, the mail system of this embodiment extracts index information of the mail to be restored from the search index. The mail system of this embodiment uses a search index to compare the search indexes of emails and perform matching. When the mail system of this embodiment can retrieve a mail with a matching Message-Id, it extracts the mail as a restoration target mail. In addition, if the mail system of this embodiment fails to retrieve a mail with a matching Message-Id, it verifies the matching rate of words appearing in mails including mails of other users, and compares it with the mail to be restored. Extract emails with a high match rate as emails to be restored. The mail system of the present embodiment restores the mail extracted by matching the search index as a new mail in the mailbox of the user who made the restoration request.

In the mail system of this embodiment, since mail saved in mailboxes of other users is restored, there is no need to add storage for backing up deleted mail. In addition, in the mail system of this embodiment, deleted mail can be restored if the mail is stored in the mailbox of the user. I never get tired of it. That is, according to the mail system of this embodiment, deleted mail can be restored without archiving the mail.

As described above, according to the mail system of the present embodiment, it is possible to restore mail deleted from a mailbox without introducing a storage for backing up mail data.

(hardware)
Here, the hardware configuration for realizing the mail system 1 according to the first embodiment will be described by taking the information processing device 90 of FIG. 11 as an example. Note that the information processing device 90 in FIG. 11 is a configuration example for realizing the mail system 1, and does not limit the scope of the present invention. The mail transmitting/receiving device 11, the mailbox 12, and the data restoring device 13, which constitute the mail system 1, may be configured as separate hardware, or may be configured as the same hardware. Further, the information processing device 90 in FIG. 11 is also a hardware configuration that implements the terminal 10 and the external mail server 100 .

As shown in FIG. 11, an information processing device 90 includes a processor 91 , a main memory device 92 , an auxiliary memory device 93 , an input/output interface 95 and a communication interface 96 . In FIG. 11, the interface is abbreviated as I/F (Interface). Processor 91 , main storage device 92 , auxiliary storage device 93 , input/output interface 95 and communication interface 96 are connected to each other via bus 99 so as to enable data communication. Also, the processor 91 , the main storage device 92 , the auxiliary storage device 93 and the input/output interface 95 are connected to a network such as the Internet or an intranet via a communication interface 96 .

The processor 91 expands a program stored in the auxiliary storage device 93 or the like into the main storage device 92 and executes the expanded program. Processor 91 functions as a central processing unit that executes processing of mail system 1 .

The main memory 92 has an area in which programs are expanded. The main memory device 92 may be a volatile memory such as a DRAM (Dynamic Random Access Memory). Also, a non-volatile memory such as MRAM (Magnetoresistive Random Access Memory) may be configured and added as the main storage device 92 .

The auxiliary storage device 93 stores various data. The auxiliary storage device 93 is configured by a local disk such as a hard disk or flash memory. It should be noted that it is possible to store various data in the main storage device 92 and omit the auxiliary storage device 93 .

The input/output interface 95 is an interface for connecting the information processing device 90 and peripheral devices. A communication interface 96 is an interface for connecting to an external system or device through a network such as the Internet or an intranet based on standards and specifications. The input/output interface 95 and the communication interface 96 may be shared as an interface for connecting with external devices.

The information processing apparatus 90 may be configured to connect input devices such as a keyboard, mouse, and touch panel as necessary. These input devices are used to enter information and settings. Note that when a touch panel is used as an input device, the display screen of the display device may also serve as an interface of the input device. Data communication between the processor 91 and the input device may be mediated by the input/output interface 95 .

Further, the information processing device 90 may be equipped with a display device for displaying information. When a display device is provided, the information processing device 90 is preferably provided with a display control device (not shown) for controlling the display of the display device. The display device may be connected to the information processing device 90 via the input/output interface 95 .

Further, the information processing device 90 may be equipped with a disk drive, if necessary. Disk drives are connected to bus 99 . Between the processor 91 and a recording medium (program recording medium) not shown, the disk drive mediates reading of data programs from the recording medium and writing of processing results of the information processing device 90 to the recording medium. The recording medium can be implemented by, for example, an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). The recording medium may be a semiconductor recording medium such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) card, a magnetic recording medium such as a flexible disk, or other recording medium.

The above is an example of the hardware configuration for enabling the mail system 1 . The hardware configuration of FIG. 11 is an example of the hardware configuration for executing arithmetic processing of the mail system 1, and does not limit the scope of the present invention. A program that causes a computer to execute processes related to the mail system 1 is also included in the scope of the present invention. Further, the scope of the present invention also includes a program recording medium on which a program relating to the processing of the mail system 1 is recorded.

The components of the mail system 1 can be combined arbitrarily. Also, the constituent elements of the mail system 1 may be realized by software or circuits.

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

1 Mail System 10 Terminal 11 Mail Transmitting and Receiving Device 12 Mail Box 13 Data Restoration Device 100 External Mail Server 131 Restoration Reception Part 132 Search Index Registration Part 133 Search Index Storage Part 134 Search Index Verification Part 135 Mail Restoration Part

Claims (10)

a mailbox having a storage area for each user;
a mail transmitting/receiving device that receives mail addressed to the user and stores the received mail addressed to the user in the storage area assigned to the user;
Data restoration in which a mail received by the mail transmitting/receiving device is acquired, and a search index is registered for at least relating words contained in the mail addressed to the user and mail information of the mail addressed to the user with respect to the mail addressed to the user. a device;
The data restoration device
extracting the word included in the mail addressed to the user when the mail addressed to the user is acquired, and registering the extracted word in the search index in association with the email information of the email addressed to the user; ,
When the restoration request mail requesting restoration of the restoration-targeted mail deleted from the mailbox is obtained, the search index is referred to, and the word associated with the mail information of the restoration-targeted mail is associated. and extracting the extracted mail information, and based on the rate of matching between the words associated with the extracted mail information and the words associated with the restoration target mail, the user who requested the restoration request mail A mail system for extracting at least one mail from among mails stored in the storage area of different users and restoring the extracted mail as the restoration target mail in the storage area of the user who requested the restoration request mail. The data restoration device
when the mail addressed to the user is obtained from the mail transmitting/receiving device, the words included in the mail addressed to the user and the position of appearance of the words are extracted, and the words extracted and the mail addressed to the user are extracted. and registering the mail information in the search index in association with the appearance position of the word,
when the restoration request mail is obtained, referring to the search index, extracting the mail information in which the appearance position of the word matches among the words associated with the restoration target mail, and extracting the extracted mail Based on the match rate between the word associated with the information and the word associated with the restoration target email, among the emails stored in the storage area of a user different from the user who requested the restoration request email 2. The mail system according to claim 1, wherein at least one mail is extracted from the mail system, and the extracted mail is restored as the restoration target mail in the storage area of the user who requested the restoration request mail. The data restoration device
registering the search index including Message-Id as the occurrence position of the word;
When the restoration request mail is obtained, the search index is referred to, and among the mails stored in the storage area of a user different from the user who requested the restoration request mail, the Message of the restoration target mail. 3. The mail system according to claim 2, wherein mail matching said word associated with -Id is extracted, and the extracted mail is restored in said storage area of the user who requested said restoration request mail as said restoration target mail. The data restoration device
When the restoration request mail is obtained, the search index is referenced to extract the mail information associated with the word associated with the restoration target mail, and the mail information associated with the extracted mail information is extracted. A mail in which the word completely matches the word associated with the restoration target mail is extracted from the mail stored in the storage area of a user different from the requesting user of the restoration request mail. 4. The mail system according to any one of claims 1 to 3, wherein the mail is restored as the mail to be restored in the storage area of the user who requested the restoration request mail. The data restoration device
When the restoration request mail is acquired, the search index is referenced to extract the mail information associated with the word associated with the restoration target mail, and the mail information associated with the extracted mail information is extracted. extracting an email having a maximum match rate between the word and the word associated with the restoration target email from emails stored in the storage area of a user different from the user who requested the restoration request email; 4. The mail system according to any one of claims 1 to 3, wherein the extracted mail is restored as the mail to be restored in the storage area of the user who requested the restoration request mail. The data restoration device
When the restoration request mail is acquired, the search index is referenced to extract the mail information associated with the word associated with the restoration target mail, and the mail information associated with the extracted mail information is extracted. emails in which the rate of matching between the word and the word associated with the email to be restored exceeds a predetermined threshold is selected from the emails stored in the storage area of a user different from the user who requested the restoration request email. 4. The mail system according to any one of claims 1 to 3, wherein at least one mail is extracted, and the extracted mail is restored as the mail to be restored in the storage area of the user who requested the restoration request mail. The data restoration device
When a deleted mail list request is obtained from the mail transmitting/receiving device, a deleted mail list response including a list of deleted mails is created in response to the deleted mail list request, and the created deleted mail list response is output to the mail transmitting/receiving device. The mail system according to any one of claims 1 to 6. Data restoration connected to a mailbox having a storage area for each user, and a mail transmitting/receiving device that receives mail addressed to the user and stores the received mail addressed to the user in the storage area assigned to the user. a device,
Obtaining mail from the mail transmitting/receiving device, outputting the normal mail when the obtained mail is a normal mail, and outputting the restoration request mail when the obtained mail is a restoration request mail requesting restoration of the restoration target mail. a restoration reception means for extracting the mail information contained in the
search index storage means for storing a search index associated with words contained in the ordinary mail and the mail information of the ordinary mail;
a search index registering means for receiving the normal mail from the restoration receiving means, and for registering in the search index the words contained in the input normal mail and the mail information of the normal mail in association with each other;
The mail information of the mail to be restored is input from the restoration receiving means, the mail information associated with the word associated with the mail information of the mail to be restored is extracted, and the mail information is associated with the extracted mail information. at least one of the emails stored in the storage area of a user other than the user who requested the restoration request email, based on the rate of matching between the word and the word associated with the email to be restored. a search index matching means for extracting two mails;
and a data restoration device for restoring the mail extracted by the search index collation means as the mail to be restored in the storage area of the user who requested the restoration request mail. When a mail addressed to the user who uses a mailbox having a storage area for each user is acquired,
extracting words contained in the mail addressed to the user;
registering a search index that associates the extracted word with mail information of mail addressed to the user;
When obtaining a restoration request mail requesting restoration of restoration target mail deleted from the mailbox, referring to the search index,
extracting the mail information associated with the word associated with the mail information of the restoration target mail;
Stored in the storage area of a user different from the requesting user of the restoration request mail, based on a match rate between the words associated with the extracted mail information and the words associated with the restoration target mail. Extract at least one email from the received emails,
A data restoration method for restoring the extracted mail as the restoration target mail in the storage area of the user who requested the restoration request mail. When a mail addressed to the user who uses a mailbox having a storage area for each user is obtained,
a process of extracting words contained in the mail addressed to the user;
a process of registering a search index that associates the extracted word with the mail information of the mail addressed to the user;
When obtaining a restoration request mail requesting restoration of restoration target mail deleted from the mailbox, referring to the search index,
a process of extracting the mail information associated with the word associated with the mail information of the restoration target mail;
Stored in the storage area of a user different from the requesting user of the restoration request mail, based on a match rate between the words associated with the extracted mail information and the words associated with the restoration target mail. a process of extracting at least one email from the received emails;
A program for causing a computer to execute a process of restoring the extracted mail as the mail to be restored in the storage area of the user who requested the restoration request mail.

Images