JP2776845B2 - Email system and email device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an e-mail system and an e-mail apparatus capable of exchanging (including circulating) e-mail.
In particular, the present invention relates to an electronic mail system and an electronic mail device for preventing falsification and loss of mail contents.

[Conventional technology]

E-mail is a method for exchanging documents quickly by electronic means using a computer and a communication network instead of exchanging documents by paper, and many e-mail systems have already been realized. To send an email,
There are two ways: sending to the same person, sending the same document to multiple people at the same time (broadcast), and sending to multiple people in a specified order (circulation).

In some cases, electronic mail has a different form of transmission than paper mail. In the case of a paper mail, a circulation format for reducing the number of paper copies is often used even for the purpose of simultaneous transmission to a plurality of parties. On the other hand, with e-mail, there is no need to reduce the number of copies due to cost. Therefore, when the purpose is a broadcast, the broadcast is used as a means. The format of the circulation in the e-mail is used when it is necessary to circulate the documents in order, such as when the discussion according to the job system is required.

[Problems to be solved by the invention]

In the circulation of e-mails, since one document often flows between a plurality of circulators and the purpose is to discuss the contents, careless change of the contents on the way must be avoided. In the case of paper documents, tampering is easy to detect, except for things like pencil writing. On the other hand, in the case of an e-mail created by keyboard operation using the document processing function of the e-mail terminal, even if the mail is falsified using the same document processing function at the circulation destination, the subsequent circulation person saw the document. The fact of tampering alone is not known. Therefore, in electronic mail, it is important to prevent falsification of the mail being circulated.

A first object of the present invention is to provide means for preventing the contents of a mail from being falsified during circulation of the electronic mail.

A second object of the present invention is to provide means for preventing a mail being circulated from being lost.

A third object of the present invention is to provide a means for guaranteeing that a mail is correctly circulated to a circulation target without loss or falsification of the mail.

A fourth object of the present invention is to provide a means for assuring who wrote what and by associating the contents of a comment or the like to a mail with the circulation person who wrote the comment.

[Means for solving the problem]

For the first purpose, in order to prevent falsification of the e-mail contents during the circulation of the e-mail, the e-mail sender must add a text area (first area) and a comment, etc., whose contents cannot be modified to the e-mail. Designation information for identifying a writing area (second area) in which writing can be freely performed is added. When the circular user attempts to write, the e-mail terminal determines whether or not it is a place where writing is permitted based on the designated information. If the above specified information cannot be written, the write request is rejected. Further, when displaying the mail on the display of the mail terminal, the text region and the writing region are displayed in different colors, thereby providing a visual clearing means for the two types of regions.

For the second purpose, the mail list information is added to the mail, and each electronic mail terminal monitors where the request issuer is located in the mail reader in response to the mail deletion request from the operator. If the e-mail deletion request is from a person other than the e-mail sender or the final circular, the deletion request is rejected.

For the third purpose, in order to ensure that the mail can be circulated to the intended circulator without falsification of the contents, information for identifying the circulator is added to the e-mail,
The information is compared with personal identification information (for example, personal identification information using a method such as a magnetic card, an IC card, or a password) input from a circular.

For the fourth purpose, information linking information that functions as a confirmation mark of the circular and information written by the circular is
The e-mail terminal attaches the mail to the mail as management information.

[Action]

According to the above-mentioned means, each reader cannot modify the contents of the mail except for the portion where writing is permitted. As a result, the mail sender can protect a portion that cannot be falsified during circulation.

Prevention of tampering during circulation requires not only the contents of e-mails at the time of transmission, but also the contents written by the circulation person during circulation. This case can also be realized by applying the above-mentioned means.

By prohibiting the mail from being circulated by the circulator, loss of the mail being circulated can be prevented.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is an example of the configuration of an electronic mail system. The communication network 19 includes a local area network, a wide area network, and the like. A plurality of mail terminals 17-1 to 17-n are connected to the communication network 19. Each mail terminal has one or more mail senders and receivers. For example, the mail sender / receiver 18-1 belongs to the mail terminal 17-1. The circulation mail created by a certain mail terminal is circulated among the mail terminals to which the designated circulation person belongs in a specified order. FIG. 1 shows an example of the configuration of a mail terminal. In FIGS. 1 and 2 and the following description of the embodiment based on these, each mail terminal has a mail box corresponding to a mail sender / receiver belonging to the mail terminal, and sends / receives mail directly between mail terminals. It takes the example of an email system that does that. However, the present invention also changes the gist of the present invention for other e-mail system configurations, for example, an e-mail system in which a mail server is provided for each mail terminal and a mail box is collectively managed there. Applicable without.

In FIG. 1, a communication interface 1 is connected to a communication network. Exchange of information with other mail terminals
All are performed via the communication interface 1. The sender / receiver identification unit 2 is used for sending or confirming the identity of a recipient when sending a mail or extracting a received mail. The received mail or the mail waiting to be transmitted is stored in the mail storage unit 3. The mail storage unit 3 has a mail box corresponding to the mail sender / receiver belonging to the mail terminal, and the received mail is put into the corresponding mail box according to the destination. Various management information such as a list of destinations of the mail system and mail transmission / reception histories are stored in the history / management information storage unit 4. The input unit 5 and the output unit 6 are contact points between the mail terminal and a human. The creation and output of mails and the exchange of commands for sending and receiving mails are all performed via the input unit 5 or the output unit 6. Input unit 5
Is composed of a keyboard, a mouse, a scanner or a handwritten character input device. The output unit 6 includes a display or a printer. CPU7 is
The program 9 stored in the memory 8 is executed. The program 9 includes a mail transmission / reception process 10 to a mail status management 15. The mail sending / receiving process 10 sends / receives mails and sends / receives control information such as status inquiry commands to / from other mail terminals via the communication interface 1. It also takes out the sent mail. It is the document processing 11 that creates a mail and writes a comment or the like to the mail. At the time of writing to the circulation mail, whether or not it is to the part where writing is permitted, the writing part recognition processing 12
Is monitoring. Document processing 11 for non-writable parts
Inform the user of this and prohibit writing. It is the writing area management 14 that creates the information on which the writing part recognition processing 12 determines whether or not writing is possible. Here, a list of writable areas is held in the form of a rectangular area based on the writing area specification at the time of mail creation. Furthermore, if the part written by the circulation person is not to be written to subsequent circulation persons, the writable area is corrected during circulation. The e-mail destination management 14 manages destination information required when transmitting an e-mail or circulating the next e-mail. In addition, the process of designating a substitute recipient or a bypass when the user is absent is also performed here. Email status management 15
Know the status of received mail or mail waiting to be sent. Also, in response to inquiries about the status of mail circulation from others,
It is also used to give an answer based on history information or the like. The data buffer 16 is a memory area in the mail storage unit 3 and the history / management information storage unit 4 for temporarily storing information being processed or frequently used. (Each component in FIG. 1 will be appropriately referred to without a figure number in the following description.) FIGS. 3 and 3 show examples of a mail configuration for preventing falsification of a mail being circulated and an example of a page in the mail. As shown in FIG. Mail header 100 for one mail
The writing area control tables 60-1 to 60-n are provided for each page constituting the mail (examples of the mail header and the writing area control table will be described later). Each page of the e-mail is composed of a body area that is not allowed to be written by the reader and a writable writing area. Each area is represented by a rectangular area. In the example of Fig. 4, the page
In the area 20-3, the mail is composed of two areas each indicated by a body area 30-1 and 30-2 and a writing area 40-1 and 40-2.

Next, the mail creating means shown in FIGS. 3 and 4 will be described below. FIG. 5 shows a procedure from creation of a mail to transmission. Document processing in step 50
The body of the mail is created by step 11. In step 51, the mail creator first specifies a writing area. The write area management 13 receives it and attaches it to a corresponding page of the mail as a write area control table. FIG. 6 shows a configuration example of the control table. The number of write areas 61 indicates the number of write areas existing on the page. Thereafter, designation of write areas for the number of write areas 62-2, 62-2, ..., 62-n
Followed by The writing area 62-i includes a set of two plane coordinates (xi
1, yi1) and (xi2, yi2). The first coordinate represents the address of the upper left corner of the rectangular writing area as relative coordinates from the top of the page. The second coordinate similarly indicates the coordinates of the lower right corner. In the example of the page in FIG. 4, the number of write areas 61 is 2 and the number of write areas 62-1 is
62-2 stores coordinates corresponding to 40-1 and 40-2, respectively.

Returning to FIG. 5, after the writing area is specified, the circulation destination is specified in step 52. The list of circulation destinations specified by the mail creator is received by the mail destination management 14, and is attached to the mail as the destination management information in the mail header. FIG. 7 shows a configuration example of the mail header 100. FIG. 7 also includes management information for proxy reception and bypass processing of mail described later. The number of circulation recipients 105 is the number of designated circulation destinations. Hereinafter, the first circular 110-1 to the final circular 110-
Until n, the IDs of the circulators are entered in the specified order.

At step 53, circulation of the mail is started. The mail transmission request is received in the mail transmission / reception processing 10. In the mail sending / receiving process 10, based on the mail sending request, information necessary for the mail header shown in FIG. 7 is set. Email ID 101
Is information for uniquely identifying the mail.
For example, the mail may be a unique number or a combination of the caller ID and the call date and time as long as the mail can be uniquely identified. The caller 102 contains the ID of the caller. If a sender / receiver identification mechanism is incorporated, the identity of the mail sender is confirmed by sender / receiver identification 2. Call date 103
Indicates the date and time of mail transmission.

The transmitted mail is circulated according to the designated circulation order. FIG. 8 shows an example of the flow of the process of the intermediate circulator except for the last circulator. As the process proceeds, information of the mail header 100 in FIG. 7 corresponding to the circulator is set. For the sake of explanation, the process of the first reader is assumed below. The subsequent processing of the circulator follows the following description. In step 201, the mail transmission / reception process 10 receives a mail transmitted from a sender (or a previous viewer in the case of a person other than the first reader) and stores the mail in the mail storage unit 3. The stored e-mail is in the e-mail waiting state 202 until an e-mail request is issued from the circulator. Step 2
When a mail retrieval request is issued in 03, the mail transmission / reception processing 10 uses the transmitter / receiver identification unit 2 to confirm in step 204 whether or not the retrieval requester is the circulation person. The result is determined in step 205, and if the user is not the person himself, the mail is not passed on and the process returns to the mail extraction waiting state 202. If it is the person himself / herself, at step 206, the date and time at which the mail is taken out is set to the take-out date 140-1 in the mail header 100 (in the case of the first circular, the same applies hereinafter). In step 207, the mail is fetched from the mail storage unit 3 and displayed on the display of the output unit 11. At this time, the body area and the writing area are displayed in different colors to clearly indicate a writable part to the reader.

Writing to the write area of the mailer for the mail 30
Details of 0 are shown in FIG. Here, an example will be described in which the written contents are protected from subsequent tampering by the circulation person, and at the same time, the association between the written contents and the circulation person can be guaranteed. Writing of a comment or the like to the mail by the circulator is performed by means of the keyboard of the input unit 5 or handwriting using the document processing 11. At this time, the document processing 11 uses the writing part recognition processing 12 to determine whether the part to be written by the circulator belongs to the writing area or the text area based on the address of the cursor or the pentatouch. Monitor with 301. Step 3 of the result
Judgment is made in 02, and writing is rejected in the case of the text area. If it is a writing area, writing is performed in step 303. For the following description of the processing, it is assumed that writing as shown in FIG. 10 has been performed. That is, the page where the mail is
20-4 is composed of a body area 30-3 and a writing area 40-3 at the time of taking out the mail. On the other hand, the writing indicated by 70 is performed. In step 304, the area 70 in which the writing has been performed is cut out as a rectangular area by the writing part recognition processing 12, and the upper left corner address and the lower right corner address are obtained as relative coordinates from the top of the page. Step 30
At 5, the write area management 13 corrects the y-coordinate value of the upper left corner address of the relevant write area in the write area control table 60 of FIG. In the example of FIG. 10, the value is corrected from the state of the write area 40-3 to a value corresponding to 40-3a. As a result, the content 70 written by the first circulator becomes an unwritable area when circulated by the next circulator, and the written content is protected. In step 306, the write management table information shown in FIG. 7 is corrected. In the writing area management 13, first, a first circulation person writing management table
The storage area 131-1 is secured, and the head address is set in the write management table address 130-1. next,
One is added to the number of writes 132-1 (the initial value is zero). First
The write page number 133-1-1 contains the page number corresponding to the page 20-4, and the first write portion 134-1-1 contains the address of the rectangular area of the write area 70 obtained in step 304. At step 307, it is determined whether or not there is the next write. If so, write 300 to the write area is executed again. However, in this case, naturally, since the first circulation writer table already exists, it is not necessary to secure the storage area, and the above processing such as setting information to a corresponding part instead of the first write part is performed. The content needs to be changed to suit the situation.

Returning to FIG. 8, if there is no writing or the writing is completed, the mail enters a transmission waiting state 209.
Although not shown in the figure, a process such as copying of the mail may be inserted in order to store the information as personal information by the circulator during this time. When a mail transmission request is issued in step 210, the mail transmission / reception processing 10 uses the transmitter / receiver identification unit 2 to confirm in step 211 whether the transmission requester is the circulation person himself or herself. The result is determined in step 212. If the user is not the person himself, the mail is not sent, and the process returns to the mail sending waiting state 209. If it is the person himself / herself, the sending date and time of the mail is set to the sending date 150-1 in the mail header 100 in step 213, and the mail is sent to the next circulation person in step 214. On the other hand, in the mail transmission waiting state, if a mail deletion request is issued from the circular at step 215, the request is a deletion request from a person other than the sender or the final circular. And returns to the mail transmission waiting state 209. As a result, the mail is prevented from being powdered by the circulating person.

In the series of processes shown in FIG. 8, the mail status management 15 collects history information as appropriate and stores it in the history / management information storage unit 4 in response to an event such as reception, retrieval, or transmission of mail. . For inquiries such as the circulation status of e-mail,
A reply is made using this history information.

In FIG. 8, the process of the circulation person has been described,
The processing flow up to step 300 is basically the same for the final circular. The differences are that there is no next circulation and that the mail can be deleted.

The above is only one embodiment of the present invention, and many other modifications can be made without changing the spirit of the invention. For example,
In FIG. 3, in a mail having no page break, it can be considered that one whole mail is made of one page. Also, the format and contents of the control tables in FIGS. 6 and 7 need not be as shown in the figures. For example, in order to obtain a more detailed mail circulation history, in the mail header of FIG. 7, information on the date and time of mail reception may be assigned to each mailer. Furthermore, not all the elements of the above embodiment are required to realize the present invention. For example, the text regions 30-1 and 30- in FIG.
In order to only protect the writers from writing to 2
The sender / receiver identification unit 2 and the sender / receiver identification processing using the same are unnecessary.

In the above embodiment, the sender / receiver identification section 2 and the sender / receiver identification processing using the same have already been described with reference to FIGS. 5 and 8. By using this and the mail header or the history information of the history / management information storage unit 4, not only the mail is lost or falsified but also the circulation status as well as the circulation status can be grasped with a guarantee. For example, it is assumed that the first circulation person retrieves a certain mail after confirming the identity, confirms the contents (there may be writing to the writing area during this time), and circulates the next circulation. In the course of this series of processing, the date and time respectively corresponding to the take-out date 140-1 and the transmission date 150-1 of the first reader of the mail header 100 in FIG. 7 are set by the mail end (FIG. 8). As a result, the date and time when the first reader took out the e-mail and the date and time when the e-mail was sent were recorded in the e-mail header under the assurance that the user was himself.
This is equivalent to pressing a confirmation mark in a conventional circulation using paper (actually, more detailed information such as the date and time of removal is added).

In addition, the mail terminal also stores the history information in the history / management information storage unit 4 by the mail status management 15 in response to events such as reception, retrieval, and transmission of mail. For example, suppose that a certain mail sender inquires of the mail terminal of the mailer about the state of circulation of the mail to a specific mailer. At this time, in the mail terminal, the mail state management 15 searches the history / management information storage unit 4 for the history information of the mail based on the mail ID, and returns the result to the mail sender. According to the result, the circulation state of the mail to the circulation person can be surely grasped with a guarantee. If the mail has not been received by the mail terminal, the mail is still being circulated to a circulator before the circulator. If the e-mail is a receiving agent but has not been retrieved by the circulator, it is in an unprocessed state. If the e-mail has been retrieved but has not been sent, the e-mail is being processed. If the e-mail has been sent, the circulation process is completed and the confirmation mark is pressed.

The function of the above-mentioned confirmation mark and the function of protecting the write contents after writing into the write area described in FIG. 9 (step 305)
In addition, by combining the contents written in the writing area and the function of associating the circulator (step 306) described in FIG. 9, the approval / disapproval of the contents of the mail and the intention of the circulator are indicated. It can be reflected under the protection of the contents of the circulation. In other words, the content of pros and cons entered by each circular is associated with the person who wrote it, and the content of each entry cannot be falsified by subsequent circulars. After confirming that the e-mail is sent and received.

In the description so far, it has been assumed that an arbitrary number of write areas can be secured at an arbitrary place in a mail. However, in the case of a mail in which only one writing area is required for comments, such as a circulation for content approval, management of the writing area can be simplified. FIG. 11 shows a typical example of such a mail configuration. The mail in FIG. 11 may be composed of a plurality of pages. The mail is composed of a continuous body area 30-4 (even if it extends over a plurality of pages) and a single writing area 40-4 following the body area 30-4. In this case, the write area control table shown in FIG. 6 is unnecessary. Also, the write management tables 131-1 to 131-n for the respective readers shown in FIG. 7 are unnecessary. Instead, an item as shown in FIG. 12 is added to the mail header 100. The coordinates corresponding to the writing area 40-4 in FIG. 11 are entered in the writing area 106. Corresponding to the writing of each circular, the coordinates corresponding to the first circular writing part 160-1 to the final circular writing part 160-n are entered. Other processes conform to the above-described embodiment.

In the processing flow of FIG. 8, the mail cannot be processed by anyone other than the circulation person. However, in this case, when the circulation person is absent for a long time, the mail stays. To avoid this, the circulator will be able to specify how to deal with absent mail. There are two ways to deal with absent mail: a method of designating a substitute recipient and a method of designating a circular bypass. In the former, an agent processes mail addressed to the circulator in place of the circulator, and in the latter, the mail system bypasses the circulated mail addressed to the circulator and sends it to the next circulator. These designations are performed by the mailer on the mail destination management 14 of the mail terminal. The mail destination management 14 reflects the specified information in the history / management information storage unit 4 based on the designation of the proxy recipient or the bypass.

Although the above-described processing method is specified by the circulation person, there are some mails that the sender does not want to show to the proxy recipients other than the circulation person. In this case, the bypass designation of the proxy receiver is performed at the time of sending the mail. By this designation, the seventh
The proxy recipient bypass designation 104 of the mail header 100 shown in FIG.

FIG. 13 shows an example of a processing flow in which the above-mentioned proxy recipient and the bypass processing are added to the processing flow of the intermediate circulation person in FIG. The processing already described with reference to FIG. 8 is omitted, and the changed part will be described below with reference to FIG. In steps 221 and 222, the mail address management is performed to determine whether or not the absentee bypass designation or the proxy recipient designation has been performed by the circulator.
14 checks using the information in the history / management information storage unit 4. If there is a bypass designation at step 221 or a substitute recipient designation, and if the substitute recipient bypass designation 104 by the sender is on at step 223, the circulation to the circulation person is bypassed. To clarify the fact of the bypass, in step 227, the removal date 140-i corresponding to the circulation person
To bypass code (for example, all 0s or all 1s)
Set. If the process is not the bypass process, when the mail is taken out, the mail is passed in step 224 if the proxy recipient is not the person who is not the person himself. However, at this time, step 225
Sets the ID of the proxy receiver to the proxy receiver 120-i.
Similarly, at the time of sending a mail, the sending process is performed in step 226 if the mail is not the principal but a substitute receiver.

〔The invention's effect〕

In the e-mail system, the broadcast function is used for ordinary information communication to multiple people.Therefore, the use of the e-mail circulation function is to examine the contents of the e-mail between the circulators according to the specified order. Then, when you come to the main. In this case, whether intentionally or accidentally, the contents of the e-mail should not be changed during circulation, or the e-mail should be lost.

According to the present invention, it is impossible for the reader to write or modify the area other than the writable area specified at the time of creating the mail, so the mail sender can circulate the mail without worrying that the contents of the mail are falsified during the circulation. There are effects that can be done. When displaying the mail on the display of the mail terminal during circulation, by displaying the writable area and the non-writable area in different colors, the viewer can visually determine the writable area. When the number of write areas is limited to one, management of the write areas can be simplified. Further, since the mailer being circulated cannot delete the mail being circulated, the mail is not lost during the circulation.

In addition, the contents written in the writable area by the reader are changed to the non-writable area at the time of circulation by the next reader, so that the writing of the reader is similarly protected from tampering. can do. Further, by retaining information on the correspondence between the written part and the circulation person who wrote it, it is possible to know who wrote what.

In addition, by combining an e-mail system having the above-described effects with a sender / receiver identification mechanism, circulation to the target e-mailer is guaranteed without loss or falsification of the e-mail. At this time, it is possible to designate a proxy recipient when a circulation person is absent or to designate a circulation bypass of the circulation person. Furthermore,
By acquiring history information in the mail header or mail terminal in response to the sending and receiving of mail and the event that occurred,
It is possible to realize a function of a confirmation mark when a circulator sees the mail and a function of guaranteeing the circulating state of the mail.

[Brief description of the drawings]

FIG. 1 is a block diagram of a mail terminal according to an embodiment of the present invention.
FIG. 2 is an example of a configuration of an e-mail system, and FIGS. 3 and 4 are examples of a mail configuration and a mail page in which a writing area that can be written by a mail circulation person and a text area that cannot be written are separately provided. FIG. 5 is an example of the flow of mail creation / transmission processing, FIG. 6 is an example of a table for managing writable areas in each page of mail, and FIG. FIG. 8 is an example of a mail header for managing correspondence with a part written by the circulator, FIG. 8 is an example of a processing flow of a circulator in the middle except for the sender and the final circulator, and FIG. FIG. 10 is an example of the flow of a write process to the write area in the middle, FIG. 10 is an example showing a change in the write area for preventing falsification of a part written to the write area by a circular, and FIG. Body area and writing to simplify writing area management 12 shows an example of a mail by limiting the area to one. FIG. 12 shows a configuration example of a mail header at that time. FIG. 13 shows a mail receiving process by a proxy receiver when a mail reader is absent or a bypass process of the reader. An example of the flow will be shown. 1 ... communication interface, 2 ... transmitter / receiver identification unit, 3
... Email storage unit, 4 ... History / management information storage unit, 5 ...
... input unit, 6 ... output unit, 7 ... CPU, 8 ... memory, 1
7-1 to 17-n: mail terminal, 19: communication network.

Claims (5)

(57) [Claims] An e-mail system for circulating an e-mail between a plurality of e-mail terminals connected to each other via a communication network, wherein the transmitting terminal for transmitting the e-mail includes, Adds first information for identifying a first area in which correction is not permitted and a second area in which the circulation person can write and circulation list information for identifying the circulation person, and receives the e-mail. The receiving terminal allows the correction of the content only in the second area of the e-mail based on the first information, and stores the identification code of the receiver of the receiving terminal and the circulation list information. Collation, if the recipient does not correspond to the sender of the e-mail or the final circulator, the e-mail requested by the recipient is not permitted to be deleted. Temu. 2. The e-mail system according to claim 1, wherein the e-mail receiving terminal is configured to execute the e-mail receiving terminal in a case where a circulation person indicated in the circulation list information has previously designated a bypass to the reception terminal. An electronic mail system, wherein information for certifying that the bypass designation processing has been performed is added to the electronic mail, and the electronic mail is transmitted to the next circular person indicated in the circular list information. 3. The e-mail system according to claim 1, wherein the e-mail receiving terminal is adapted to be operated when the circulation person indicated in the circulation person list information gives an instruction for designation and identification of an agent in advance. An e-mail system wherein reception is permitted when the recipient is the agent. 4. The electronic mail system according to claim 3, wherein the transmitting terminal adds the information for designating a proxy receiver to the electronic mail according to an instruction of a sender and transmits the electronic mail. The mail receiving terminal attaches information for certifying that the processing of the proxy receiver bypass designation has been performed to the e-mail, and transmits the e-mail to the next circulation person indicated in the circulation list information. Characterized e-mail system. 5. An e-mail device which circulates an e-mail to a receiving terminal which is another e-mail device connected via a communication network. Adding first information for identifying a first area in which correction is not permitted and a second area in which a circulation person can write, and circulation list information for identifying the circulation person;
The receiving terminal that has received the electronic mail allows the content to be modified only in the second area of the electronic mail based on the first information, and the identification code of the receiver of the receiving terminal and the circulation. Collation with the recipient list information, and when the recipient does not correspond to the sender of the e-mail or the final circulation person, deletion of the e-mail requested by the recipient is not permitted. Email device.