JPH11175419A - Electronic mail transmitting and receiving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the burden imposed on a client device which has many restrictions because it is portable by converting attached data with a conversion method that corresponds to a decoding means that is incorporated in a client device of the address in accordance with the address of a mail. SOLUTION: A gateway device 102 receives a mail that is transmitted and confirms its content. If it is not a mail with data attached, it transfer the mail data as it is to a client device 105 in a remote place, and in the case of a mail with data attached, it confirms a decoding means that is prepared by a client according to a table that is prepared beforehand. It cuts out an attached data part and separates the attached data part from the other mail part. Afterward, data that is converted into a mail part after cutting and separation is attached again (replaced). This is repeated as many times as the number of the attached data. Thus, the device 102 sends a mail to the client device 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic mail transmission / reception system, and in particular, it is impossible to provide, as a client device, means for decoding all various conversion formats of attached data due to functional and physical limitations. Or
The present invention relates to an e-mail transmission / reception system including a small client device in which a decryption unit cannot be easily added or changed when a conversion format is frequently added / changed.

[0002]

2. Description of the Related Art In a mail system usually used on the Internet, a device called a mail server is installed on a LAN network, and all mail addressed to a user is received and stored as a proxy once, and is requested by the user. Mail is transferred to the client device of the user who has made the request. Conversely, when the user wants to send a mail, he sends the mail body to be sent together with the mail transmission request command to the mail server device.

In some systems, there is a mail gateway device. Normally, when a mail server device and a client device use different mail data communication protocols, the mail gateway device performs protocol conversion on the difference between the protocols so that data exchange between the mail server and the client can be performed without any problem. Often serve as an intermediary.

[0004] An electronic mail is generally composed of a destination, a title, a text, a date, attached data and the like for each mail. Also, there are mails without attached data, but in the case where there is attached data, in general, the attached data is often larger than the mail body in terms of data amount.

[0005] In the above cases, the attached data is often compressed or converted by a unique method. However, the conventional mail transmission / reception system uses a special mail in consideration of the attached data conversion method. The delivery method was never realized, and the mail delivery method taking the amount of attached data into consideration was rarely realized.

[0006] In Japanese Patent Application Laid-Open No. 8-32617, image data is stored in a gateway device that performs conversion between protocols, and only the storage destination is notified to a mail. We are devising a scheme to access the data based on the information and reduce the communication traffic volume. this is,
The concept of data sharing is trying to reduce communication traffic.

[0007]

A plurality of conversion formats are usually used for conversion of attached data. For example, in the Internet, Base64 unencode is generally used.
e is used, but there is also a unique format. In some cases, the data may be attached in a form of encryption that can be reduced by a data compression unit or decrypted only by a specific person. Therefore, there is no problem if the means for decoding all the conversion formats that can be received is prepared on the client device, but only the decoding means for the specific conversion format should be prepared due to physical or functional restrictions. There are some client devices that cannot do this. In such a case, even if the client device receives the mail, it cannot decode the attached data because it does not have means for decoding the conversion format in which the attached data is converted. Therefore, the attached data cannot be confirmed or used.

[0008] Further, when exchanging e-mail with a portable personal computer or a portable information device when going out, a connection method to a mail server is usually made using a wired or wireless telephone line. In such a case, a telephone line is generally slower than a line such as a LAN, so it is necessary in terms of cost and time to reduce the amount of data to be transferred and perform efficient data transfer. Conventionally, no consideration has been given to changing the data to be transferred via a line.
If the client device receives an email containing a large amount of attached data because it is transferred in the same way regardless of whether it is a low-speed line or a low-speed line, it will take a considerable amount of time until the reception is completed, and the usability of the user will increase. Very bad. Further, when returning / transferring such attached data, the same attached data is transmitted again from the client device to the mail server device, which wastes time.

[0009] Furthermore, a plurality of conversion formats are usually used for the conversion format of the attached data.
Since the means for decoding all the conversion formats that may be received may not be prepared, if the sending client device tries to send the attached data in a form to be received by the destination, the destination It is necessary to convert the mail to a format that can be decoded by the client device and send the mail. In particular, when returning / forwarding an e-mail with attached data, it is necessary to confirm which decryption means the attached client device has prepared for the attached data and return / forward or return / forward the same. It is necessary to decipher the attached data of the original mail once, convert it to a format that can be deciphered again by the return / forwarding destination, and then decide whether to return / forward,
It would be very distracting to the user.

[0010]

According to a first aspect of the present invention, there is provided an electronic mail transmission / reception system, comprising: a mail server device, a mail client device, and a mail gateway device. A means for relaying a mail transmission request from the device, a means for analyzing the contents of the mail received from the server to confirm the presence or absence of the attached mail, and a determination as to which decoding means the destination client device prepares A plurality of conversion means for converting the table and the attached data, and means for converting the attached data by a conversion method corresponding to the decryption means provided in the client device of the destination according to the destination of the mail, and Replace the attached data with the converted data and send the replaced mail to the client device And an e-mail transmission / reception system.

According to a second aspect of the present invention, there is provided the electronic mail transmitting / receiving system according to the first aspect, wherein only the attached data is separated and stored from the target mail, and the stored attached data is managed. When,
Means for determining whether the client has also requested the sending of attachments, means for not sending the attached data when the client does not send the attached data, and means for returning these when the client device sends back / forward mail. Even if the attached data attached to the mail that is the source of the forwarded / forwarded mail is not sent at the same time, the client device saves the information of the mail that is the source of the reply / forward that is present in the mail as a key. Means for retrieving and extracting attached data, and transmitting the retrieved data to a mail server attached to the returned / forwarded mail.

According to a third aspect of the present invention, there is provided the electronic mail transmitting / receiving system according to the second aspect, wherein when the reply / forwarded mail is received, the attached mail attached to the original mail of the reply / forwarded mail. After the data is retrieved by retrieving the data stored on the gateway device, from among the plurality of conversion format devices provided in the gateway device, the data is sent to the decryption device provided in the client device to which the reply / transfer is provided. An e-mail transmission / reception system wherein a corresponding conversion means is selected, converted, re-attached to a reply / transmission mail, and transmitted to a mail server device.

[0013]

FIG. 1 shows a schematic configuration of an embodiment of the present invention. As a mail transmitting / receiving system, a mail server device (101), a normal mail client device (103, 104), a mail gateway device (102), a modem (106, 107) connected to the mail gateway, a telephone line connected to the modem , A mail gateway device (10
5) (usually located at a remote location remote from the mail gateway device). There is no particular limitation on the number of mail client devices (103, 104, 105).

FIG. 2 shows a mail server device (101),
It is an example of an internal configuration of a client device (103, 104, 105) mail gateway device (102).

The ROM (20) mainly includes the CPU (201).
2) Memory such as RAM (203), storage device (20
4), input / output devices (205, 206), display devices (20
7, 208) and a communication board (209). A mail server device (101), a client device (103, 104, 105), a mail gateway device (102), and a personal computer are often used. As the client device (105) connected to the modem (106, 107), a portable personal computer or a PDA (Personal Digital) is used.
A portable communication terminal device called “Assistant” is often used.

In this embodiment, the mail server device (10
1) is connected to the Internet communication line and LA
It is also possible to retrieve mail from outside N.

All mail addressed to a user within the LAN or from within the LAN, such as the Internet, is stored once in the mail server (101).

When the mail server (101) receives a transfer request from the client device (103, 104, 105), the client (103,
104, 105). An example of the mail transmission request / transfer protocol during this time is a protocol called POP3. Mail client device (103,
104, 105), a function for viewing the received mail, a function for requesting the server (101) to transfer the mail addressed to itself in the server and receiving the same, a function for transmitting a newly created mail, and a function for receiving the received mail. It is equipped with a reply / forward function that adds these replies or adds comments based on the e-mail and sends it to the sender or another destination.
"Send" and "Reply" to operate each function
Buttons and menus such as "Transfer" are prepared.

The mail gateway device (102) is often used for normal protocol conversion and temporary buffering of communication data. The configuration according to the present invention is used to connect a mail server to a remote client device by connecting to a telephone line.

The type of communication protocol between these devices is not related to the present invention. In general, mail communication-related protocols such as POP3 and SMTP are often used over TCP / IP protocols in LAN communication.

FIG. 3 shows an example of the contents of a mail used in the present invention. The mail information used in the present invention includes destination [To] (301), cc destination (302), sender [from] (303), and date [Date] (30).
4), mail ID [MailID] (305), ID of the mail that is the source of this mail [In-reply-T]
o] (306), title [Subject] (307),
There is a text (308) and attached data (309). "The ID of the mail that originated this mail [In-reply-
"To] (306)" is used in the reply / forward mail, and the ID of the mail that is the source of the reply / forward is described. If there is this item, this mail can be determined as a reply / forward mail.

In the present invention, if the mail contains such information, the format of the e-mail to be used does not depend on a specific format. For example, RFC (RequestForCom) often used on the Internet
ment) 822 standard (Standard format)
t for APRA Internet textm
Essage) specifies a format for expressing these items.

(Embodiment 1) Gateway device (102)
Are the respective client devices (10
3, 104, 105) confirmed the attached data decryption means actually prepared among various attached data conversion methods, and a mail address (602) and a decryptable conversion method (603) were paired. It is stored in the form of a table (FIG. 6) on the gateway device (102).

Next, it is assumed that a mail is sent from the Internet to the client device (105). In this case, the sent mail data is stored on the mail server device (101). (701) Next, the client device (105) passes through the modem (106, 1).
At 07), a command is issued to the gateway device (102) to send (download) the received mail to the client device (105). (702) The gateway device (102) confirms that the received mail is a download command, and issues the same command to the mail server device (101) as it is.

(703) Mail server device (101)
After receiving the received mail download command, after confirming from whom the request is received, the gateway device (102) receives the mail addressed to the user in its own storage area.

(704): Gateway device (102)
Receives the transmitted mail and confirms its contents.
If the mail is not a mail with attached data, the mail data is directly transferred to the remote client device (105).

(705) (706): If it is a mail with attached data, a table prepared in advance (FIG. 6)
, Check the decryption means prepared by the client. (707): Then, the attached data part is cut out and separated into the attached data part and the other mail part.

FIG. 4 shows an example in which a mail is separated into an attached data part and other parts. The attached data thus cut is converted by a conversion method corresponding to the decoding method confirmed in the table (FIG. 6).

(708) Thereafter, the data converted into the separated mail part is attached (replaced) again. (70
9) This is repeated by the number of attached data. (710)
After the above is completed, the gateway device (102) sends an e-mail to the client device (105).

As described above, the remote client device (105) receives the mail from the mail server device (101) via the gateway device.

(Embodiment 2) Consider a case where a mail is sent from the Internet to a remote client device (105).

In this case, the sent mail data is
It is stored on the mail server device (101). (80
1) Next, the gateway device (10) is transmitted from the remote client device (105) via the modems (106, 107).
Issue a received mail download command to 2).

(802) The gateway device (102) confirms that the received mail is a download command,
A similar command is issued to the mail server device (101) as it is. Upon receiving the received mail download command, the mail server device (101) confirms from whom the request was made, and then transmits a mail addressed to a user in its own storage area to the gateway device (102). I do.

(803) Gateway device (102)
Receives the transmitted mail and confirms its contents.
(804) If the mail is not a mail with attached data, the mail data is directly transferred to the remote client device (105). (805, 806) If the mail has attached data, the decryption means prepared by the client is confirmed. While confirming the mail ID (305), the attached data part (309) is cut out and separated into the attached data part and the other mail parts.
(807) The attached data that has been cut is the mail ID (30
Along with 5), it is stored in the storage device on the gateway device. The storage method is such that actual data can be extracted by searching using the mail ID (305) as a key.

FIG. 5 shows an example of the storage method. The mail ID to which the attached data to be saved is attached to the storage device
A table (501) in which a pair (502) and an address (503) for storing the table (501) are recorded and an actual storage area (504) are prepared in the storage device of the gateway device (102), and the separated attached data is stored. At this time, the mail ID and the stored address information are added to the table (501). (808)
This process is performed for all attached data.

(809, 810, 811 and 812) Next, the attached data is processed according to the preset contents. If "Send both mail attachments" is specified, the original mail data is transmitted to the client device (105) as it is. If "transfer only mail text" is specified, the attached data is separated and only the mail part is transmitted to the remote client device (105). At this time, a comment notifying the user that the gateway device (102) cuts and saves the attached data may be added to the end of the mail. By the above method, the remote client device (1
05) receives mail from the mail server device (101) via the gateway device (102).

The user receives the received mail and confirms the contents. (813) When attempting to “return” or “forward” the mail, the user usually selects “return” or “forward” while the mail to be returned is displayed on the client device (105). Select a button or menu, create a mail with comments added to the mail that was returned or forwarded, and perform the "Send" operation.

When the client device (105) performs this transmission operation, the client device (105) checks the ID (305) of the original mail of the created reply / forward mail, and checks "ID of the mail from which this mail originated." (306). Then, this mail is transmitted to the gateway device (102) together with the mail transmission command. According to the present invention, at this time, the client device (105) does not need to reattach the data attached to the mail from which the mail originated and send the data to the gateway device (102). Only the body of the mail needs to be transmitted.

(814, 815) Client Device (1
The gateway device (102) that has received the mail transmission instruction from (05) confirms the contents of the mail, and if there is no “mail ID from which this mail originates” (306), the mail data is left as it is. It transmits to the mail server device (101) and requests the mail server device (101) to transmit to the destination.

(816, 817, 818) If it is confirmed that "the ID of the mail that is the source of this mail" (306) is present, the "ID of the mail that was the source of this mail"
Gateway device (102) using (306) as a key
The attached data stored in the storage device (204) is retrieved, the corresponding data is extracted, and added to the mail data from the client device. (819) Thereafter, the message is transmitted to the mail server device (101), and the mail server device (101) is requested to transmit the message to the destination.

(Embodiment 3) Gateway device (102)
Are the respective client devices (10
3, 104, 105) confirmed the attached data conversion means actually prepared among various attached data conversion methods, and the mail address (602) and the convertible conversion method (603) were paired. It is stored in the form of a table (FIG. 6) on the gateway device (102).

(901, 902, 903) When the gateway device (102) receives the reply / forward mail from the client device (105), it checks the destination and the presence / absence of attachment. Specifically, in the same manner as described in claim 2, "the ID of the mail that is the source of this mail" (30
6) is determined based on the presence or absence.

(904, 905, 906, 907, 90
8,909) and the gateway device (102)
Using the “mail ID from which this mail originated” (306) as a key, the attached data stored in the storage device (204) of the gateway device (102) is searched, and the relevant data is extracted. Using the conversion means corresponding to the decryption format of the client device, the attached data is converted, attached, and sent to the mail server device (101).

[0044]

According to the first aspect of the present invention, the client device does not need to prepare a plurality of means as the means for decoding the attached data, but only needs to prepare a single decoding means. The burden can be reduced in a client device which is portable and has many restrictions. Also convert /
Decryption method can be added by updating only the gateway device.
Since there is no need to modify the client device, it is easy to add a conversion / decryption method.

According to the second aspect of the present invention, when "replying" and "forwarding" an attached mail, the data attached to the mail from which the mail originated is transmitted from the client device to the gateway device. Since there is no need to reply at the same time, it is possible to reduce the amount of mail transmission data. Therefore, unnecessary data transfer can be eliminated to improve the efficiency of the communication path and reduce the communication time, so that the usability of the user can be improved.
If the setting is made to save the attached data on the gateway device side, it is not necessary to save the attached data on the client side. There is also an advantage that the capacity can be reduced.

According to the third aspect of the present invention, the client device does not need to prepare a plurality of attached data converting means, but only needs to prepare a single converting means. Therefore, the burden can be reduced in a client device having many restrictions. At the time of “reply” and “forward”, the user does not need to pay attention to the conversion format of the data attached to the mail that is the source of “reply” and “forward”.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a connection example between devices constituting the present invention.

FIG. 2 is a block diagram showing an example of a main internal configuration of each device constituting the present invention.

FIG. 3 is a diagram showing an example of an internal configuration of an electronic mail.

FIG. 4 is a diagram showing an example in which an electronic mail is separated into a mail main body and attached data.

FIG. 5 is a diagram illustrating an example of a management table for storing attached data and a storage method.

FIG. 6 is a diagram showing a decoding format included in a client device of each mail destination.

FIG. 7 is a flowchart according to claim 1;

FIG. 8 is a flowchart according to claim 2;

FIG. 9 is a flowchart according to claim 3;

[Explanation of symbols]

 101 Mail Server 102 Gateway Device 103 Client Device 104 Client Device 105 Client Device 106 Modem 107 Modem 201 CPU 202 ROM 203 RAM 204 Storage Device 205 Input / Output I / F 206 Keyboard / Mouse 207 Display Control Unit 208 Display 209 Communication Board

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04L 29/06

Claims (3)

[Claims] In a mail transmission / reception environment in which a mail server device, a mail client device, and a mail gateway device are provided therebetween, means for relaying a mail transmission request from a client device on a mail gateway device, and receiving from a server. Means for analyzing the contents of the e-mail and confirming the presence / absence of the attached e-mail, a table capable of determining which decryption means the destination client device is preparing, and a plurality of conversion means for converting the attached data. Means for converting attached data according to a destination corresponding to the mail by a conversion method corresponding to the decoding means provided in the client device of the destination; and replacing the attached data with the converted data and sending the replaced mail to the client. An e-mail transmission / reception system, comprising: a device for receiving the e-mail. 2. The electronic mail transmission / reception system according to claim 1, wherein means for separating and saving only the attached data from a target mail, means for managing the stored attached data, and a client requesting the transmission of the attached data. Means for determining whether or not the client device does not send the attached data when the client device does not send the attached data, and means for generating the returned / forwarded mail when the client device sends the returned / forwarded mail. Even if the attached data attached to the received mail is not sent at the same time, the client device searches for the attached data stored using the information of the mail that is the source of the reply / forward existing in the mail as a key. Means for taking out and attaching the returned / forwarded mail to the mail server. Transmission and reception system. 3. The electronic mail transmission / reception system according to claim 2, wherein when the reply / forward mail is received, the attached data attached to the mail which is the origin of the reply / forward mail is stored on the gateway device. After retrieving the extracted data by searching, the conversion means corresponding to the decryption means provided in the client device to which the reply / transfer is provided is selected from the plurality of conversion format means provided in the gateway device. An e-mail transmission / reception system, wherein the e-mail transmission / reception system re-attaches the reply / sent mail after conversion and sends the reply / mail to the mail server device.