Electronic mail system and electronic mail access acknowledging method

Claims

What is claimed is:

1. An electronic mail server used in a distributed type of network with a plurality of networked electronic mail servers each having terminals connected thereto comprising:

a preparing means for preparing a transmitted mail message, when a submitted mail message is received from one of the terminals connected thereto, according to the submitted mail message and program information actuated to return, when the main body of the transmitted mail message is accessed and read at a destination terminal, an acknowledgement by mail of the access to the electronic mail server;

a return mail program generating means for generating the program information;

a transmitting means for transmitting the transmitted mail message prepared by said preparing means;

a judging means for judging whether or not a mail message received, after said transmitted mail message is transmitted by said transmitting means, is acknowledgement that the transmitted mail message has been accessed and read, which is returned from said destination terminal in response to actuation of said program information; and

a storing means for storing therein, when it is judged by the judging means that the mail message is the acknowledgement that the mail message has been accessed and read, a result of a transmission of the transmitted mail message prepared by said preparing means as information indicating that the transmitted mail message was accessed and read.

2. An electronic mail server according to claim 1; wherein said preparing means has a generating means for generating said program information in response to a request of transmission from a terminal connected to said distributed type of network.

3. An electronic mail server used in a distributed type of network with a plurality of networked electronic mail servers each having terminals connected thereto comprising:

a setting means for setting identification information for identifying a submitted mail message as an object for transmission when the submitted mail message is received from one of the terminals connected thereto;

a preparing means for preparing a transmitted mail message according to said submitted mail message, the identification information set by said setting means, and program information actuated to return a mail message including access acknowledgement and said identification information to the electronic mail server when a main body of the transmitted mail message is accessed and read at a destination terminal;

a return mail program generating means for generating the program information based on said identification information;

a transmitting means for transmitting the transmitted mail message prepared by said preparing means;

a judging means for judging whether a mail message received after said transmitted mail message is transmitted by said transmitting means is an acknowledgement that the transmitted mail message has been accessed and read, which is returned in response to actuation of said program information from said destination terminal;

an extracting means for extracting said identification information set by said setting means from said received mail when it is judged by said judging means that the received mail is the acknowledgement that the transmitted mail message has been accessed and read; and

a storing means for storing therein a result of transmission of the transmitted mail message prepared by said preparing means and corresponding to the identification information extracted by said extracting means as information indicating that the transmitted mail message was accessed and read.

4. An electronic mail server according to claim 3; wherein said preparing means has a generating means for generating said program information in response to a request of transmission from a terminal connected to said distributed type of network.

5. An electronic mail server used in a distributed type of network with a plurality of networked electronic mail servers each having terminals connected thereto comprising:

a setting means for setting identification information for identifying a submitted mail message as an object for transmission when the submitted mail message is received from one of the terminals connected thereto;

a storing/managing means for storing therein and managing the identification information set by said setting means in correspondence to said submitted mail message and access information indicating that a main body of the submitted mail message has not been accessed nor read at a destination terminal;

a preparing means for preparing a transmitted mail message according to said submitted mail message, the identification information set by said setting means, and program information actuated to return an acknowledgement mail message including an acknowledgment of access and said identification information to the electronic mail server when the main body of the transmitted mail message is accessed and read at the destination terminal;

a return mail program generating means for generating the program information based on said identification information;

a transmitting means for transmitting the transmitted mail message prepared by said preparing means;

a judging means for judging whether or not a mail message received after said transmitted mail message is transmitted by said transmitting means is an acknowledgement that the transmitted mail message has been accessed and read, which is returned in response to actuation of said program information from said destination terminal;

an extracting means for extracting the identification information set by said setting means from said received mail message when it is judged by said judging means that the received mail message is the acknowledgement that the transmitted mail message has been accessed and read; and

a changing means for changing access information concerning a mail message having the identification information extracted by said extracting means from among mail messages stored in and managed by said storing/managing means to an access state.

6. An electronic mail server according to claim 5 further comprising:

an inquiring request accepting means for accepting a request for inquiring the contents stored in and managed by said storing/managing means from a terminal connected to said distributed type of network,

a retrieving means for retrieving contents corresponding to said terminal in response to acceptance by said inquiring request accepting means;

a responding means for returning a result of retrieval by said retrieving means to said terminal through said distributed type of network.

7. An electronic mail server according to claim 5; wherein said preparing means has a generating means for generating said program information in response to a request of transmission from a terminal connected to said distributed type of network.

8. An electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of electronic mail servers; wherein each of said electronic mail servers has:

a preparing means for preparing a transmitted mail message, when a submitted mail message is received from one of the terminals connected thereto, according to the submitted mail message and program information actuated to return, when a main body of the transmitted mail message is accessed and read at a destination terminal, an acknowledgement by mail that the transmitted mail message has been accessed and read to the electronic mail server;

a return mail program generating means for generating the program information at the electronic mail server;

a transmitting means for transmitting the transmitted mail message prepared by said preparing means to the electronic mail server to which the destination terminal is connected among said plurality of electronic mail servers;

a judging means for judging whether or not a mail message received, after said transmitted mail message is transmitted by said transmitting means, is an acknowledgement that the transmitted mail message has been accessed and read, which is returned in response to actuation of the program information from said destination terminal; and

a storing means for storing a result of transmission of the transmitted mail message prepared by said preparing means as information that the transmitted mail message has been accessed and read when it is judged by said judging means that the transmitted mail message is an acknowledgement that the transmitted mail message has been accessed and read;

wherein each said terminal returns a response according to the program information actuated when the main body of said received mail message transmitted thereto is accessed and read when the transmitted mail message transmitted from said transmitting means is received from an electronic mail server, from among said plurality of network electronic mail servers, to which the destination terminal is connected.

9. An electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers; wherein said each electronic mail server comprises:

a setting means for setting, when a submitted mail is received from one of the terminals connected thereto, identification information for identifying the submitted mail message as an object for transmission;

a preparing means for preparing a transmitted mail message according to said submitted mail message, the identification information set by said setting means, and program information actuated to return a mail message including an acknowledgement that the transmitted mail message has been accessed and read and said identification information to a networked electronic mail server when a main body of the transmitted mail message is accessed and read at a destination terminal;

a return mail program generating means for generating the program information based on said identification information;

a transmitting means for transmitting the transmitted mail message prepared by said preparing means to an electronic mail server, from among said plurality of networked electronic mail servers, to which said destination terminal is connected;

a judging means for judging whether or not a mail message received after said transmitted mail message is transmitted by said transmitting means comprises information that the transmitted mail message has been accessed and read, said received mail message returned in response to actuation of said program information from said destination terminal;

an extracting means for extracting the identification information set by said setting means from said received mail message when it is judged by said judging means that the received mail is an acknowledgement that the transmitted mail message has been accessed and read; and

a storing means for storing a result of a transmission of the transmitted mail message prepared by said preparing means and corresponding to the identification information extracted by said extracting means as information that the transmitted mail message has been accessed and read;

wherein each said terminal returns a response according to the program information actuated when the main body of said transmitted mail message transmitted thereto is accessed and read when a transmitted mail message transmitted by said transmitting means is received from the electronic mail server, of said plurality of networked electronic mail servers, to which the terminal is connected.

10. An electronic mail system comprising a distributed type of network, a plurality of electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of electronic mail servers; wherein said each electronic mail server comprises:

a setting means for setting, when a submitted mail message is received from one of the terminals connected thereto, identification information for identifying the submitted mail message as an object for transmission;

a storing/managing means for storing therein and managing the identification information set by said setting means in correspondence to said submitted mail message and access information indicating that a main body of the submitted mail message has not been accessed nor read at a destination terminal;

a preparing means for preparing a transmitted mail message according to said submitted mail message, the identification information set by said setting means, and program information actuated to return by mail an access acknowledgement and said identification information to the server when the main body of the transmitted mail message is accessed and read at a destination terminal;

a return mail program generating means for generating the program information based on said identification information;

a transmitting means for transmitting the transmitted mail message prepared by said preparing means to an electronic mail server, of said plurality of electronic mail servers, to which said destination terminal is connected;

a judging means for judging whether or not a mail message received after said transmitted mail message is transmitted by said transmitting means is an access acknowledgement returned in response to actuation of said program information from said destination terminal;

an extracting means for extracting identification information set by said setting means from said received mail message it is judged by said judging means that the received mail message is an acknowledgement that the transmitted mail message has been accessed and read; and

a changing means for changing access information for a mail message including the identification information extracted by said extracting means from among mail message stored in and managed by said storing/managing means to an accessed state;

wherein each said terminal returns a response according to the program information actuated when the main body of the transmitted mail message is accessed and read when said transmitted mail message transmitted from said transmitting means is received from the electronic mail server, of said a plurality of electronic mail servers, to which the terminal is connected.

11. An electronic mail access acknowledging method applied to an electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers, said method comprising the steps of:

receiving a submitted mail message at a transmitting electronic mail server of said plurality of networked electronic mail servers from one of the terminals connected thereto;

preparing a transmitted mail message, according to the submitted mail message as an object for transmission and to program information actuated to return, when a main body of the transmitted mail message is accessed and read at a destination terminal, an acknowledgement by mail of the access to the transmitting electronic mail server;

generating the program information at the electronic mail server;

a transmitting step of transmitting the transmitted mail message to a destination electronic mail server, of said plurality of networked electronic mail servers, to which the destination terminal is connected from said transmitting electronic mail server;

receiving a mail message returned according to the program information actuated when the main body of the transmitted mail message is accessed and read when said destination terminal receives the transmitted mail message from said destination electronic mail server; and

storing, as information that the transmitted mail message has already been accessed and read, a result of a transmission of the transmitted mail message according to an access acknowledgement in the returned mail message on said transmitting electronic mail server.

12. A computer-readable medium having stored thereon a program causing a computer to execute an electronic mail access acknowledging method applied to an electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers, said method comprising the steps of:

receiving a submitted mail message at a transmitting electronic mail server of said plurality of networked electronic mail servers from one of the terminals connected thereto;

preparing a transmitted mail message, according to the submitted mail message as an object for transmission and to program information actuated to return, when a main body of the transmitted mail message is accessed and read at a destination terminal, an acknowledgement by mail of the access to the transmitting electronic mail server;

generating the program information at the electronic mail server;

a transmitting step of transmitting the transmitted mail message to a destination electronic mail server, of said plurality of networked electronic mail servers, to which the destination terminal is connected from said transmitting electronic mail server;

receiving a mail message returned according to the program information actuated when the main body of the transmitted mail message is accessed and read when said destination terminal receives the transmitted mail message from said destination electronic mail server; and

storing, as information that the transmitted mail message has already been accessed and read, a result of a transmission of the transmitted mail message according to an access acknowledgement in the returned mail message on said transmitting electronic mail server.

13. An electronic mail access acknowledging method applied to an electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers, said method comprising the steps of:

receiving a submitted mail message at a transmitting electronic mail server of said plurality of networked electronic mail servers from one of the terminals connected thereto;

setting identification information for identifying the submitted mail message as an object for transmission on said transmitting electronic mail server;

preparing a transmitted mail message, on said transmitting electronic mail server, according to said submitted mail message, the identification information, and program information actuated to return a mail message including an acknowledgement of the access and said identification information to the transmitting electronic mail server when the main body of the transmitted mail message is accessed and read at a destination terminal;

generating the program information at the electronic mail server based on the identification information;

transmitting the transmitted mail message to a destination electronic mail server, of said plurality of networked electronic mail servers, to which said destination terminal is connected from said transmitting electronic mail server;

receiving a returned mail message, when said destination terminal receives the transmitted mail message from said electronic mail server as a destination for transmission according to program information actuated when the mail body of the transmitted mail message is accessed and read;

extracting the identification information from the returned mail message according to an access acknowledgement in the returned mail on the transmitting electronic mail server; and

storing, as information that the transmitted mail message has already been accessed and read, a result of a transmission of the transmitted mail message in correspondence to the identification information on said transmitting electronic mail server.

14. A computer-readable medium having stored thereon a program causing a computer to execute an electronic mail access acknowledging method applied to an electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers, said method comprising the steps of:

receiving a submitted mail message at a transmitting electronic mail server of said plurality of networked electronic mail servers from one of the terminals connected thereto;

setting identification information for identifying the submitted mail message as an object for transmission on said transmitting electronic mail server;

preparing a transmitted mail message, on said transmitting electronic mail server, according to said submitted mail message, the identification information, and program information actuated to return a mail message including an acknowledgement of the access and said identification information to the transmitting electronic mail server when the main body of the transmitted mail message is accessed and read at a destination terminal;

generating the program information at the electronic mail server based on the identification information;

transmitting the transmitted mail message to a destination electronic mail server, of said plurality of networked electronic mail servers, to which said destination terminal is connected from said transmitting electronic mail server;

receiving a returned mail message, when said destination terminal receives the transmitted mail message from said electronic mail server as a destination for transmission according to program information actuated when the mail body of the transmitted mail message is accessed and read;

extracting the identification information from the returned mail message according to an access acknowledgement in the returned mail on the transmitting electronic mail server; and

storing, as information that the transmitted mail message has already been accessed and read, a result of a transmission of the transmitted mail message in correspondence to the identification information on said transmitting electronic mail server.

15. An electronic mail access acknowledging method applied to an electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers, said method comprising the steps of:

receiving a submitted mail message at a transmitting electronic mail server of said plurality of networked electronic mail servers from one of the terminals connected thereto;

setting identification information for identifying said submitted mail as an object for transmission on said transmitting electronic mail server;

storing and managing the identification information in correspondence to said submitted mail message and access information indicating that a main body of said submitted mail message has not been accessed nor read at a destination terminal on a memory previously prepared on said transmitting electronic mail server;

preparing a transmitted mail message according to submitted said mail message, the identification information, and program information actuated to return a mail message including an access acknowledgement and said identification information to the transmitting electronic mail server when the main body of the transmitted mail message is accessed and read at said destination terminal;

generating the program information at the electronic mail server based on the identification information;

transmitting the transmitted mail message to a destination electronic mail server, of said plurality of networked electronic mail serves, to which the destination terminal is connected from said transmitting electronic mail server;

returning, when said destination terminal receives the transmitted mail message from said destination electronic mail server, said returned mail message according to the program information actuated when the main body of the transmitted mail message is accessed and read;

extracting the identification information from the returned mail message according to the access acknowledgement in the returned mail message on said transmitting electronic mail server; and

changing the access information for a mail message having therein the extracted identification information, of mail messages stored and managed on said memory, to the information indicating that the mail message has been accessed and read on said transmitting electronic mail server.

16. A computer-readable medium having stored thereon a program causing a computer to execute an electronic mail access acknowledging method applied to an electronic mail system comprising a distributed type of network, a plurality of networked electronic mail servers connected to said distributed type of network, and a plurality of terminals connected to said plurality of networked electronic mail servers, said method comprising the steps of:

receiving a submitted mail message at a transmitting electronic mail server of said plurality of networked electronic mail servers from one of the terminals connected thereto;

setting identification information for identifying said submitted mail as an object for transmission on said transmitting electronic mail server;

storing and managing the identification information in correspondence to said submitted mail message and access information indicating that a main body of said submitted mail message has not been accessed nor read at a destination terminal on a memory previously prepared on said transmitting electronic mail server;

preparing a transmitted mail message according to submitted said mail message, the identification information, and program information actuated to return a mail message including an access acknowledgement and said identification information to the transmitting electronic mail server when the main body of the transmitted mail message is accessed and read at said destination terminal;

generating the program information at the electronic mail server based on the identification information;

transmitting the transmitted mail message to a destination electronic mail server, of said plurality of networked electronic mail serves, to which the destination terminal is connected from said transmitting electronic mail server;

returning, when said destination terminal receives the transmitted mail message from said destination electronic mail server, said returned mail message according to the program information actuated when the main body of the transmitted mail message is accessed and read;

extracting the identification information from the returned mail message according to the access acknowledgement in the returned mail message on said transmitting electronic mail server; and

changing the access information for a mail message having therein the extracted identification information, of mail messages stored and managed on said memory, to the information indicating that the mail message has been accessed and read on said transmitting electronic mail server.

FIELD OF THE INVENTION

This invention relates to electronic mail system, and, more particularly, to an electronic mail server having a function for checking whether a transmitted mail has been accessed and read or not on a distributed type of network.

BACKGROUND OF THE INVENTION

In a mail system over a LAN (Local Area Network) in which a mail server can provide centralized control over mail transactions between client devices, it is possible for a transmitting site to check whether a receiver has received a transmitted mail or not. In a LAN, the state in which a client device in the receiving site has accessed a mail message sent to the device is regarded as the received state.

On the other hand, in a network such as The Internet using the TCP/IP protocol, the network forms a distributed type of electronic mail system, so that it is impossible to put all mail transactions on the network under centralized control.

In recent years, however, in association with technological progress in the field of the distributed type of electronic mail as described above, the technology enabling a transmitting site to check whether a receiving side has received a transmitted mail has been proposed, for instance, in Japanese Patent Laid-Open Publication No. HEI 2-116239, Japanese Patent Laid Open Publication No. HEI 6-195275, and Japanese Patent Laid-Open Publication No. HEI 7-56837. Namely, Japanese Patent Laid-Open Publication No. HEI 2-116239 discloses the technology in which, when an electronic mail is transmitted between mail servers, the transmitting site first appends to the mail message a request for returning acknowledgement of the mail and then transmits the mail message. The receiving site returns a confirmation according to the request for returning an acknowledgement when the receiving site receives the mail.

Japanese Patent Laid-Open Publication No. HEI 6-195275 discloses the technology in which, independent from the mail system, a server managing mail information is provided in each of the transmitting sites and receiving sites to execute additional functions such as enabling each server to check whether or not a transmitted electronic mail has been accessed and read. Japanese Patent Laid-Open Publication No. HEI 7-56837 discloses the technology in which, when a LAN terminal finishes transmission of data from a communication server, information indicating end of transmission is transmitted as a receiving acknowledgement message to the transmitting terminal.

In the electronic mail systems based on the conventional technology as disclosed in the patent publications described above, confirmation of receiving, namely acknowledgement that the mail has been accessed and read is sent to the transmitting site when the receiver takes an electronic mail from the server. Thus for the mail system, transmission of a mail message from the transmitting site to the receiving site is completed, but the timing for confirming that the mail has been accessed and read is not defined on the system. For this reason, it can not firmly be confirmed that a receiver has accessed and read the mail, and sometimes the state indicating that the mail is not accessed nor read may continue for a while.

Also the electronic mail system incorporating therein configuration for realizing additional functions for checking that a transmitted mail has not been accessed nor read, or that a transmitted mail has been accessed and read in a server in each of the transmitting and receiving sites respectively as disclosed in Japanese Patent Laid-Open Publication No. HEI 6-195275 described above, is suited to a small scale LAN in an in-house system. However, in a large network system such as The Internet, which is distributed over a wide area, specific functions are allocated to each server. Thus, it has not been feasible to unify all the functions with the additional functions as described above.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an electronic mail server, an electronic mail system, and a method of checking that an electronic mail has been accessed and read, and a computer-readable medium recording medium in which a program causing a computer execute the method is recorded, in which accuracy in checking that a transmitted mail message has been accessed and read in the receiving site can be made higher while reducing the necessity for upgrading of the existing system.

With the present invention, when a mail message is transmitted, the transmitted mail message has program information actuated to return, when the mail body is accessed and read at a destination terminal, an acknowledgement that the mail was accessed and read to the transmitting device. When information as to whether the mail message has been accessed and read or not is obtained from the destination terminal, the result of transmitting the mail message is stored as data indicating that the mail was accessed and read. Thus, the destination terminal is required only to access and read a main body of the mail for returning a response confirming that the mail was accessed and read. For this reason, it is not required to add any specific function for checking whether or not a transmitted mail has been accessed and read to a destination terminal or a destination electronic mail server. Accordingly, it is possible to improve accuracy in checking whether a transmitted mail has been accessed and read in the receiving site while reducing the necessity to upgrade the existing system.

With the present invention, when a mail message is transmitted, the transmitted mail message has program information actuated to return, when the main body of the mail is accessed and read at the destination terminal, acknowledgement by mail that the mail has been accessed and read as well as the identification information for the mail message to the transmitting site. When information as to whether the mail has been accessed and read is obtained from the destination terminal, the identification information is extracted from the received mail and the result of transmitting the mail message corresponding to the identification information is stored as information indicating that the transmitted mail was accessed and read. Thus, the destination terminal is only required to open the main body of the mail message for confirming that a transmitted mail has been accessed and read. For this reason, it is not necessary to add any specified function for confirming that a transmitted mail has been accessed and read to a destination terminal or a destination electronic mail server. Further an operation for distinguishing a transmitted mail message not accessed yet from a transmitted mail message already accessed is simplified according to the identification information. It is possible to have higher accuracy in checking whether a transmitted has been accessed and read or not in the receiving site with the necessity for upgrading of the existing system reduced.

With the present invention, identification information and access information indicating that a main body of a transmitted mail message has not been accessed nor read is stored at a destination terminal in correspondence to each mail. When a mail message is transmitted, a transmitted mail message has program information actuated to return, when the main body of the mail has been accessed and read at the destination terminal, an acknowledgement by mail that the mail message has been accessed and read as well as identification information for the mail message to the transmitting site is transmitted. When information that the mail has been accessed and read is obtained from the destination terminal according to the received mail message, identification information is extracted from the received mail message, and access information for the transmitted mail message corresponding to the identification information is changed to information indicating that the mail has been accessed and read. Thus, the destination terminal only needs to return acknowledgement of access opening the main body of the mail message. For this reason, it is not necessary to add any specific function for checking whether or not a transmitted mail message has been accessed and read to the destination terminal or the destination electronic mail servers. Further, for changing information indicating that a transmitted mail has not been accessed nor read to information indicating that the mail has been accessed and read is simplified by using the identification information. It is possible to improve the accuracy in checking that a transmitted mail has been accessed and read in the receiving site with the necessity of upgrading the existing system.

With the present invention, when a request for inquiring contents stored and managed is accepted from a terminal, contents corresponding to the requesting terminal is searched according to the acceptance and a search result is returned. Thus information indicating that any transmitted mail stored and managed in the system has been accessed and read can be supplied in real time.

With the present invention, program information is generated in response to a transmission request from a terminal. Thus, an operation for preparing program information is executed only when a mail message is prepared. With this feature, the system load for control other than for mail preparation can be alleviated.

With the present invention, an electronic mail server transm