JPH03174847A - Electronic mail system - Google Patents

Abstract

PURPOSE:To facilitate the system buildup and its operation and management by using one kind of processing units for a server equipment, a client equipment and an equipment having both functions switchingly. CONSTITUTION:Processing units 1, 2 are of the same hardware configuration except difference from connection interfaces with the network. Thus, they are used for server equipments, client equipments or equipments having both functions depending on programs loaded to them as to whether they are for server, client or both. Thus, the arrangement of processing units at system buildup is made easy and the operation and management after system buildup are facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic mail system for exchanging electronic documents and messages via a communication network.

[Conventional technology]

Conventional e-mail systems include, for example, a centralized server system in which multiple client devices are connected to one server device, as shown in FIG.

There is a distributed server system in which a plurality of server devices are provided as shown in FIG.

In the centralized server method, even if e-mails are exchanged between adjacent client devices, they always go through the server, which increases communication costs if the physical distance between the server and client devices is large. There is a problem. Furthermore, since the load is concentrated on the server device, there is a drawback that the number of client devices that can be connected simultaneously is limited due to the processing capacity limit of the server device.

On the other hand, in a distributed server system, by installing multiple servers in the system, the physical distance between the server and client devices can be reduced, reducing communication costs compared to the centralized server system. can. In addition, by increasing the number of server devices, the system as a whole can be connected simultaneously and the number of client devices can be increased, and the number of clients that can be connected simultaneously per server device can be relatively small. can be constructed using relatively inexpensive processing equipment.

[Problem to be solved by the invention]

In the conventional distributed server type email system mentioned above,
Because the server and client devices used different types of processing devices, it was difficult to decide how to arrange these two types of processing devices when initially building the system, and it was difficult to decide how to arrange the two types of processing devices after the system was built. When moving, etc., it is necessary to relocate the processing equipment, and when the processing capacity of a certain server equipment is insufficient, it is necessary to install additional processing equipment for the server equipment, etc. This mainly affects system construction and operation. There was a problem that management was complicated.

A first object of the present invention is to facilitate the system construction and operational management of a single distributed server type electronic mail system.

In addition, in conventional e-mail systems, in order to make each mailbox available only to the user who owns it, an owner password is registered for each mailbox, and the password is The system was such that the mailbox could not be accessed unless the user entered the following information.

For this reason, for example, if the owner of a certain mailbox wants to have a third party handle mail addressed to him/her, there is an inconvenience in that he/she must tell that person his/her owner password. .

A second object of the present invention is to make it possible to grant the right to use one's mailbox to a third party without telling the owner password of one's own mailbox to a third party other than oneself.

Furthermore, in conventional e-mail systems, when sending e-mail from a client device to a server device or between server devices, it is not always necessary to check whether the e-mail transmission is meaningful or not before sending it. The email I took the trouble to send was not examined carefully by
There have been problems in which delivery becomes impossible due to incorrect destination information, or transmission has to be canceled due to insufficient memory on the receiving side.

A third object of the present invention is to improve the processing efficiency of the system by avoiding the above-mentioned wasteful sending of e-mails.

[Means to solve the problem]

In order to achieve the above-mentioned first object, the present invention enables one or both of a client function and a server function to be installed in the same type of processing device, so that each processing device can be used as a server device or a client function can be used as a server device. You can freely choose whether to use it as a device or as a device that combines both.

In addition, for the second purpose above, it is possible to register multiple pairs of passwords for obtaining usage rights for each mailbox and the types of usage rights obtained thereby, and The corresponding usage rights are now given to the password used that matches the password.

Furthermore, when sending an email for the third purpose above, control information including email destination information and required memory amount information is postponed, and the receiving side uses that information to
- The main body of the email is now sent only when you allow the email to be accepted.

[Effect]

According to the present invention, since the same type of processing device can be switched and used as a server device, a client device, or a device that is used for both, it becomes easy to arrange the processing devices when constructing a system.

Therefore, server devices can be installed appropriately depending on the characteristics of the organization to which the application is applied, and if the processing capacity of a certain server device is insufficient, one of the processing devices that was previously used as a client device can be installed. All you have to do is switch to using one as a server device.

In addition, the password to be used can be freely set/cancelled by the owner of each mailbox as necessary.
You can control usage rights in detail, such as granting only appropriate usage rights to a third party for the necessary period, or permanently granting specific usage rights to your secretary or colleague. It is.

Additionally, when sending an e-mail to a server device that accommodates the destination mailbox of a certain e-mail, if the destination information is postponed, the server device on the receiving side will not be able to send the e-mail if a forwarding request has been made to that mailbox. will return the destination information of the forwarding destination mailbox. This allows the sending server device to switch the destination of the email to the server device that accommodates the forwarding destination mailbox, without transmitting the main body of the email to the receiving server device.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the hardware configuration of an embodiment of an e-mail system according to the present invention. The processing device 1 includes a local area network (hereinafter referred to as LAN) 3
It has a connection interface with another processing device 1 that is connected to the same LAN via LAN3, and further connects to a different LAN from itself via communication control bag N5 and communication network 4. The processing equipment that is being used! !
1 and a processing device directly connected to the communication network 4! It is possible to communicate with 2. The processing device 2 has a connection interface with a communication network 4, and communicates with other processing devices 2 via the communication network 4 and further with a communication control bag [
5 and the processing device 1 via the LAN 3.

Processing device 1 and processing device! 2 may have the same hardware structure except for the connection interface to the network, and depending on whether the program installed on it is for the server, client, or both.
Each device can be used as a server device, a client device, or a dual-purpose device for both. The hardware of these processing device i1 and processing device 2 is, for example,
Workstation 2050 manufactured by Hitachi, Ltd.,
This can be easily realized by installing an appropriate communication interface board in accordance with the type of LAN or communication network to be connected to a PC9801 series personal computer manufactured by NEC Corporation.

As the LAN 3, Hitachi Token Ring Network TR-41 Hitachi Workstation Network WSNET manufactured by Hitachi, Ltd., and various other LANs provided by various manufacturers can be used. Further, as the communication network 4, a communication control device that can use any one of a public telephone network, a circuit-switched data network, a packet-switched data network, an 15DN, a private telephone network, a leased line network, or a composite network thereof. Reference numeral 5 is for interconnecting the LAN 3 and the communication network 4, and an appropriate model may be selected and used depending on the type of LAN and communication network to be connected.

Examples of usable communication control devices 5 include Hitachi Communication Station 20 manufactured by Hitachi Seisakusho Co., Ltd.
There is 01C8.

FIG. 4 shows the processing bag [1 and the processing device! 2 is a block diagram showing a hardware configuration of an embodiment of a processing device according to the present invention, which can be used as either of the following. Of the components shown in FIG. 4, the NCU interface 19 and NCU 24 may be omitted when used as the processing device 1, and conversely, the LAN interface 18 may be omitted when used as the processing device 2. It's okay.

In the processing device shown in FIG. 4, the CPU II executes calculations according to programs stored in the ROM 12, which is a read-only memory, and the RAM 13, which is a readable/writable memory. Keyboard 21. Display 22. It controls input/output to and from the magnetic disk 23, and controls the LAN interface 18 and N
Data communication is performed with other processing devices via the CU interface 19. Keyboard input section 152 Display control section 16. The disk control unit 17 includes a keyboard 21, a display 22 . Magnetic disk 23 and CPU 1
1 or between the ROM 12 and RAM 13. Further, the LAN interface 18 serves as a communication interface with other processing devices via the local area network LAN, and the NC1J interface 19 serves as a communication interface with the NCU 24 and other processing devices via the wide area communication network. .

The programs and data that define the operation of the processing device are
R by executing the initialization program stored in the magnetic disk 23 and stored in the ROM 12.
It is loaded on AM13 and executed.

FIG. 5 is a diagram showing an example of how to use the memory area formed by the RAM 13, and the 08 section 31 includes basic operations of the processing device such as memory management, program execution control, input/output control, etc. The specified basic program and the data necessary for its execution are stored. Application program department 3
2, the magnetic disk 23 is loaded by the above basic program.
A group of application programs read from , and a group of data necessary for their execution are stored. These application programs are executed in parallel under the control of the basic program, thereby allowing the processing device to simultaneously execute a plurality of operations defined by each application program.

FIG. 6 shows the processing device as a client device, a server device,
Alternatively, this example shows an example of how to use the application program section 32 when used as a device for both. In this example, the client program 33 and the data group 34 that define the operation as a client device, and the client program 33 and the same data group 34 as a server device are The server program 35 and the data group 36 that define the operation of the server are allocated to different memory spaces. However, it is also possible to allocate the same memory space for both, and read the corresponding program and data from the magnetic disk each time depending on which program is executed. When used, the server program 35 and the data group 36 may be omitted;
If the processing device is used only as a server device, the client program 33 and the data group 34 may be omitted.

As shown in FIG. 7, the names of programs to be started can be registered in the application program startup table stored in the magnetic disk 23, and either the client program name or the server program name can be registered in this table. Alternatively, if both are registered, the basic program can download the application program corresponding to the program name registered in the table from the magnetic disk 23 to the program section 3.
2 are sequentially read and the read application programs are executed, whereby each processing device operates as either a client device, a server device, or a device that functions as both.

Next, the e-mail exchange operation using this system will be explained.

Of the processing device 1 and the processing device 2, the one that executes the client program 33 operates as a client device. FIG. 8 shows an example of a functional block diagram showing the configuration of the client program 33.

The document editing 41 provides a man-machine interface for editing a document to be sent as the main body of an e-mail and storing it in a document file 46 provided in the magnetic disk 23.0 Document editing operations are performed by 1. Similar to a word processor, a mouse 20. Keyboard 21. This can be done using the display 18, and the edited document is stored in the document file 46 with a document name via the document management 44.

The sending control 42 provides a man-machine interface for sending emails.
When a mail sending command is input from 1, a mail sending operation screen 1, for example, as shown in FIG. 9 is displayed on the display 22. When the user enters the execution command after keying in the necessary information, the input information is checked for errors. If there is no error, the document specified by the send document name is sent to the document file via the document management 44. 46 and transmits it to the server device via the communication control 45 along with mail control information such as the sender, destination, designated delivery date and time. At this time, the destination server device to which each client device should send mail is the server device that accommodates the mail pocket of the user who is performing the mail sending operation. As a method for determining the partner server device, for example, a method of storing the correspondence between the user ID and the network address of the server device in advance in a server registration table provided in the magnetic disk 23 of each client device, Either a method of enabling communication with only one server device and setting its network address in a DIP switch or the like, or a method of having the user input the network address of the server device with which to communicate may be used.

On the other hand, the reception control 43 provides a man-machine interface for each user to receive mail delivered to his or her mailbox, for example.

When the user inputs a mail reception command from the keyboard 21, a mail reception operation screen as shown in FIG. 10 is displayed on the display 22. When the user enters the execution command after keying in the necessary information, the input information is checked for errors, and if there are no errors,
A mail reception request is transmitted via the communication control 45 to the server device that accommodates the user's mailbox, with the name of the mailbox from which the user wishes to receive mail and the mail search conditions as parameters. On the server device side,
Returns the email name, sender, date and time of reception, etc. for all emails that meet the specified search conditions among the emails that are accumulated in the specified mailbox. These contents are displayed! ! 22. The user
When a specific email is selected from the displayed emails and a request is made to receive the email body, a request to receive the email body is sent to the server device with the email ID of the email selected by the user as a parameter. . When the main body of the e-mail is received from the server device, its contents are displayed on the display 2.
2.

Of the processing device 1 and the processing device i2, the one that executes the server program 35 operates as a server device (including the case where both the client program 33 and the server program 35 are executed by the same processing device). 2, both programs 33 and 35 for the client and the server are always executed, and the client program 33 on the processing device i2 can only communicate with the server program 35 on the same processing device as itself. FIG. 11 shows an example of a functional block diagram showing the configuration of a server program.

In the magnetic disk 23 of one server device, mailboxes 59-1. of a plurality of users are stored.・・・・・・59-n
can be accommodated. Further, each server device can simultaneously communicate with a plurality of client devices and server devices via the client-to-client communication control 57 and the server-to-server communication control 58. The mailbox group registration table 55 includes the group names of all mailbox groups that can be specified as delivery destinations for mail from each server device and the address on the communication network of the server device in which they are accommodated. Register the correspondence relationship.

The client-to-client communication control 57 controls communication with the client device, and starts the mail reception 51 when an e-mail is sent from the client device. At this time, mail control information including the sender of the mail, the destination, the designated delivery date and time, and the amount of memory required to store the mail itself is forwarded from the client device. The email address is
It consists of the group name of the mailbox group that includes the mailbox to which the mail should be delivered, and the box name for identifying each mailbox within the group. The mail reception 51 searches the mailbox group registration table 55 for the group name corresponding to the destination of the received mail, thereby obtaining the communication network address of the server device to which the mail is to be delivered.

moreover.

The mail reception 51 secures memory or files corresponding to the memory amount of the received mail body, and if it is determined that the mail can be accepted, sends the mail body to the client device via the client communication control 57. The sending permission is returned, and then the main body of the mail sent from the client device is received and stored in the reserved memory or file.

Note that if the group name corresponding to the destination included in the postponed mail control information is not registered in the mailbox group registration table 55, if it fails to secure the necessary memory or file, or if the mail control information is If it is determined that the e-mail cannot be accepted, such as when the e-mail is fraudulent, the e-mail reception 51 returns a message that the e-mail cannot be accepted to the client device, and stops accepting the e-mail.

The mail received as described above is passed from the mail reception 51 to the mail delivery 52. The e-mail delivery 52 immediately sends the e-mail to the communication network address of the delivery destination server device previously requested by the e-mail reception 51 when the specified date and time arrives if the e-mail is not an e-mail with a specified delivery date and time. Send an email to the corresponding delivery destination server device via the server communication control 58: If the destination server device is the server device itself, the email is sent via the server communication control 58. It will be passed to your own mail receipt 53.

An e-mail sent from a mail delivery 52 of a certain server device is received by a mail reception 53 via a server-to-server communication control 58 of the server device that accommodates the mailbox of the destination of the e-mail. The mail receiving unit 53 sends the mail to the mailbox corresponding to the destination box name (59-1, . . . , 5
9-n).

When sending e-mails between server devices, the e-mail control information is postponed in the same manner as when e-mails are sent from the client device to the server device. If the box does not exist in the own server device or if the necessary memory or files cannot be secured, a message indicating that the mail cannot be received is returned and reception of the mail is discontinued.

Further, when the client-to-client communication control 57 receives a mail reception request from the client device, the mail retrieval 54
Start. The mail retrieval 54 retrieves the mail name, sender,
The reception date and time etc. are returned, and when a request to receive the body of the specified mail is sent from the client device, the body of the mail is read from the mailbox and sent to the client device.

In the password registration table 60, a plurality of pairs of a password and the type of mailbox use right obtained by the password can be registered for each mailbox. When a mailbox access request is received from a client device, mail reception 51 and mail extraction 54 determine whether a password is registered for the mailbox. If a password is registered, only access requests permitted by the type of usage rights corresponding to the password sent from the client device are accepted.

In the forwarding destination registration table 61, for each mailbox, the name of a forwarding destination mailbox to which mail delivered to that mailbox should be forwarded can be registered. The mail reception 53 determines whether or not a forwarding destination is registered for a certain mailbox when the mail control information of a mail addressed to a certain mailbox is postponed, and determines whether the forwarding destination is registered. If so, the forwarding destination information is returned to the server device that sent the email.

The server device that is the sender of the email delivers the email to the forwarding destination mailbox.

Next, a method of representing a mailbox name used to represent the destination, sender, forwarding destination, etc. of a mail in this electronic mail system will be explained.

In this system, groups of mailboxes can be set in appropriate units within the system, and smaller groups can also be set within each of these groups. Note that it is necessary to give each group a local name for locally identifying groups belonging to the same family group. As a result, groups of mailboxes can be arranged hierarchically within the system, and the inclusion relationship between groups can be represented by the structure shown in FIG. 12.

In FIG. 12, each node of the tree represents a group of mailboxes, and the name given to each link represents the above-mentioned local name. In this case, for example, the group name of the node indicated by A in the diagram is / n 1 / n 2 / n 3 / n using the local names given to the links that make up the bus from the root of
It can be expressed as 4. Furthermore, by adding links as shown by the broken lines in Figure 13,
As the group name of the same A, / a 1 and /
The two aliases n 1 / n 2 / a 2 can also be used.

Furthermore, it is necessary to give each mailbox a local box name so that it is unique within the lowest mailbox group in which it is included. Then, the mailbox name is expressed by a combination of the above group name or its alias and the above box name.
The mailbox names of the mailbox with local name X included in group A in the diagram are: ■ / n 1 / n 2 / n 3 / n 4
/ x ■ / a 1 / x ■ / n 1 / n 2 / a 2 / x of 3
One can be used.

〔Effect of the invention〕

According to the present invention, the arrangement of the server device and the client device can be freely changed by simply changing the way in which the server program and the client program are installed on each processing device. It is easy to deploy, and operation management after system construction is also easy.

Furthermore, since a plurality of passwords can be set for controlling usage rights for each mailbox, detailed control of usage rights is possible when the same mailbox is shared by multiple users.

Furthermore, when sending mail from a client device to a server device, or when delivering mail between server devices, if the mail body is sent only when the conditions for accepting the mail body on the receiving side are met, there will be unnecessary waste of the mail body. transmission can be avoided and the processing efficiency of the system can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an e-mail system according to the present invention, FIGS. 2 and 3 are block diagrams showing the structure of a conventional e-mail system, and FIG. 4 shows a client device and a server device. 5 to 7 are examples of how the memory area of the processing device is used. FIG. 8 is a functional block diagram showing the client program configuration, and FIGS. 9 and 10. is an example of a screen displayed on the display of a client device, FIG. 11 is a functional block diagram showing the operation of the server device, and FIGS. 12 and 13 show the relationship between the hierarchical structure of mailbox groups and group names. It is an explanatory diagram. 1...processing device, 2...processing device, 3
...Local area network, 4...
...Communication network, 5...Communication control device. Figure 2, figure 3, email number 45a, figure 7, stem 7, figure 10, figure I2 figure, figure 13

Claims (1)

[Claims] 1. Equipped with a plurality of processing devices and a client function equipped with at least one of a client function that provides a man-machine interface for sending and receiving emails, and a server function that delivers and stores emails. A first communication means for each processing device (hereinafter referred to as a client device) to communicate with at least one processing device equipped with a server function (hereinafter referred to as a server device), and a and a second communication means for direct communication with any server device, and each server device has one or more groups of mailboxes each having a unique name within the system (hereinafter referred to as group name). and as email address information,
Specify the group name of the group to which the recipient's mailbox to which the mail is to be delivered belongs, and the name (hereinafter referred to as box name) for identifying the mailboxes within that group. Also, in each server device, A means is provided to store the group names of all mailbox groups installed in the system and the correspondence between the server devices in which each group is installed, so that each server device can receive emails requested to be delivered by client devices. By searching the storage means from the box name included in the destination information, the server device that accommodates the mailbox to which the mail is to be delivered is determined, and the mail is sent directly to the other party's server device via the second communication means. An e-mail system configured to deliver. 2. The e-mail system according to claim 1, wherein the first
An electronic mail system characterized in that the means of communication is a local area network. 3. In the e-mail system according to claim 1, the second
An e-mail system characterized in that the communication means is a telephone network, a packet-switched data network, a circuit-switched data network, an ISDN, a leased line network, or a composite network thereof. 4. The e-mail system according to claim 1, wherein when the same processing device serves as both the client device and the server device, the first communication means is realized by software. 5. The e-mail system according to claim 1, wherein all the server devices and client devices are composed of the same type of processing device. 6. In the e-mail system according to claim 1, it is possible to hierarchize the mailbox groups, and by giving each group a unique local name among the groups belonging to the same parent group, each mailbox group can be An e-mail system characterized in that a group name is represented by a pair of a group name of its parent group and a local name under that parent group. 7. In the e-mail system according to claim 6, the group name of each mailbox group is the group name of any upper group that includes the group;
An e-mail system characterized in that a set of local names is used as an alias to uniquely identify a group directly under its superior group. 8. In the e-mail system according to claim 1, a mail stored in a certain mailbox can be sent from any client device capable of communicating with a server device in which the mailbox is stored using the first communication means. An e-mail system characterized by being able to receive e-mails. 9. In the e-mail system according to claim 1, means for storing a password for each mailbox to obtain the right to use each mailbox, and a means for storing a password for each mailbox, and a means for storing a password for obtaining the right to use each mailbox, and a means for storing a password for each mailbox when requesting access to each mailbox from a client device. An e-mail system comprising means for permitting access to a mailbox only when a transmitted password matches the above-mentioned stored password. 10. The e-mail system according to claim 9, further comprising: means for storing a plurality of pairs of passwords and types of usage rights permitted for the passwords for each mailbox; When a password matches one of the above-mentioned memorized passwords, a method is provided to permit access only to the mailbox that corresponds to the type of usage rights stored as a pair with the matching password. An e-mail system characterized by the following. 11. In the e-mail system according to claim 1, when sending e-mail from the client device to the server device, between the server devices, and from the server device to the client device, first, control information necessary for mail delivery is transmitted. The electronic mail system is characterized in that the sending side sends the main body of the mail only when the receiving side of the mail permits sending of the main body of the mail based on the control information. 12. The e-mail system according to claim 11,
E-mail destination information is included in the control information sent from the client device to the server device, and if the server device cannot identify the other server that corresponds to the above destination information, the client device is not allowed to send the main body of the e-mail. An e-mail system characterized by: 13. The e-mail system according to claim 11,
Each server device is provided with a means for storing destination information to which mail addressed to the mailbox it accommodates should be forwarded, and the destination information of the mail is included in the control information that is forwarded between server devices. If the server device stores forwarding destination information for the mailbox corresponding to the above destination information, the server device returns that destination information to the sending server device, and the sending server device returns the destination information to the receiving side server device. An electronic mail system characterized in that an attempt is made to deliver mail to a mailbox corresponding to destination information returned from a server device. 14. The e-mail system according to claim 11,
The control information to be postponed includes information on the amount of memory required to store the body of the email, and the recipient of the email reserves the appropriate amount of memory, and if memory cannot be reserved, the email is sent. An e-mail system characterized by not allowing the sender to send the main body.