JP2003101587A - Reception mail server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select and obtain only desired electronic mails. SOLUTION: Upon reception of a notification informing arrival of a mail this reception mail server notifies to a mobile machine 1B JUID which is a unique ID, number of attached files, and kind information of the attached files to the mail. When the notification is received the mobile machine 1B sends RETR command of 'RETR O, JUID' to an extended POP3 server 8, in a transaction state of the POP3. The extended POP3 server 8 delivers only the mail data specified by the JUID through the command to the mobile machine 1B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving mail server that delivers mail by executing post office protocol (POP) processing.

[0002]

2. Description of the Related Art Digital mobile communication systems (P
DC (Personal Digital Cellular telecommunication)
system), GSM (global system for mobile communi
Cation), IS-54, IS-95, etc.) are remarkably widespread, and support for data communication is becoming more important in mobile communication. Therefore, a PDC-P (PDC Packet) method using a packet switching method, a GPRS (General Packet Radio System) method based on GSM, an HDR (High Data Rate) method based on IS-95, and the like have been developed. By using communication using such packets, it is possible to send and receive e-mail and access the Internet. In addition, the current circuit switching method is used to send and receive electronic mail and access the Internet.

[0003]

As a protocol for delivering electronic mail, POP3 (Post Office Protocol) is used.
Version 3) is commonly used. POP3 is the most popular e-mail receiving protocol at present, is defined by RFC (Request for Comments) 1939, and uses the port 110. This P
FIG. 7 shows an example of a sequence when the POP3 server, which is a receiving mail server equipped with OP3, delivers an electronic mail to a mobile device. As shown in FIG. 7, when the mobile device receives a mail acquisition request from the user, the mobile device establishes a TCP (Transmission Control Protocol) connection with the POP3 server using the TCP port with the port number 110. Then, the login sequence of POP3 is performed. This login sequence authenticates the user. When the user is authenticated in the login sequence, the POP session goes into a transaction state.

Here, in order for the mobile device to acquire the information of the electronic mail addressed to itself stored in the mailbox,
When the UIDL command is transmitted to the POP3 server as shown in FIG. 7, the POP server notifies the message number and unique ID of the e-mail together with the positive response “+ OK”. This message number is 1, 2, ... and 1
The unique ID is POP3.
An arbitrary character string determined by the server, 0x21 to 0x7
It consists of 1 to 70 characters in the range of E. In the illustrated example, two e-mails addressed to the mobile device are stored in the mailbox.
The unique ID of 2 is notified to the mobile device. When the mobile device receiving this message wants to acquire the message of message number 2, it issues a RETR command with an argument of "2" to PO.
Send to P3 server. The POP3 server uses this RET
When receiving the R command, the mail data corresponding to the message number 2 indicated by the argument is transmitted to the mobile device. When an attachment file is attached to this e-mail, the mail data consists of the text and the attachment file. When the mobile device receives the mail data corresponding to the message number 2, the mobile device sends a DELETE command to delete the electronic mail to POP3. The argument of this DELE command is the message number 2 corresponding to the delivered mail data.

P receiving the DELE command with the argument "2"
In order to delete the mail data of message number 2, the OP3 server sets a deletion flag for the mail data and sends an affirmative response “+ OK” to the mobile device. Upon receiving the positive response “+ OK”, the mobile station sends the end command Q
Send the UIT command to the POP3 server. As a result, the POP3 server in the updated state and receiving the QUIT command deletes the mail data for which the deletion flag is set from the mailbox, and sends an affirmative response “+ OK” to the mobile device. As a result, POP3 is logged off, and T
The CP connection will be closed.

As described above, the POP3 can request the information of the electronic mail addressed to itself and have only the arbitrary electronic mail among the notified electronic mail delivered. For that purpose, it is necessary to issue a UIDL command and have the e-mail information notified. However, the maximum unique ID notified as e-mail information is 70 characters, and since this unique ID is notified for the number of e-mails addressed to the device itself stored in the mailbox, a large amount of data is notified. Will be done. Then, there arises a problem that the radio frequency resource limited for this notification may be squeezed. Further, since the notified e-mail information is only the message number temporarily assigned to the e-mail and the unique ID of the e-mail, the e-mail information cannot be obtained. Therefore, there is a problem that the user of the mobile device cannot determine whether or not the email is unnecessary, and normally all emails must be acquired. As described above, there is a problem that it is difficult to specify and obtain only a desired electronic mail from the POP3 server. Further, there is a problem in that, when an attached file is attached to the electronic mail, it is impossible to specify and obtain either the text or the attached file from the POP3 server.

Further, while the mobile device is acquiring an electronic mail from the POP3 server, the mobile device may move into a tunnel or the like, causing a squelch failure, or may move out of the service area and be disconnected. The sequence in this case is shown in FIG. After some sequence is performed as shown in FIG. 8, the DELE command with the message number msg as an argument
Suppose that 3 servers are notified. In this case, the POP3 server sets the delete flag for the electronic mail corresponding to the argument msg and activates the auto logout timer. Here, it is assumed that the squelch is cut off or the service area is cut off and the wireless line is disconnected. Then, it is assumed that the user makes a login request for POP3 again, knowing that the user has been disconnected. In this login request, the mobile device sends a USER command with the user name username given for authentication as an argument to the POP3 server. However, since the auto logout timer is activated, the USER command is not accepted and the login request results in an error. Therefore,
From the POP3 server, a negative response "-ERR" is returned to the mobile device, and the login is rejected. In this case, although the DELE command was sent with the message number msg as an argument, the corresponding e-mail was not deleted from the mailbox.

After the autologout timer times out, the user can log in again, but at this time, the DELE command with the already transmitted message number msg as an argument is invalid. Therefore, although the DELE command is sent with the message number msg as an argument, the corresponding e-mail is not deleted from the mailbox. Here, to delete the email, send the DELE command again with the message number msg as an argument, and
IT command must be sent.

[0009] Furthermore, while the mobile device is acquiring an e-mail from the POP3 server, the mobile device moves into a tunnel or the like, causing squelch disconnection, or moving out of service area and disconnected. In some cases, the machine will not request a re-login. The sequence in this case is shown in FIG. It is assumed that the DELE command with the message number msg as an argument is notified to the POP3 server after some sequence is performed as shown in FIG. In this case, the POP3 server sets the delete flag for the electronic mail corresponding to the argument msg and activates the auto logout timer. here,
It is assumed that the squelch is cut off or the service area is cut off and the wireless line is disconnected. Then, the mobile device has timed out the auto logout timer without making a re-login request. At this time, the DELE command having the already transmitted message number msg as an argument is invalid. Therefore, although the DELE command is sent with the message number msg as an argument, the corresponding e-mail is not deleted from the mailbox.

Therefore, a first object of the present invention is to provide a receiving mail server which can specify and obtain a desired electronic mail or a specified text or an attached file of the electronic mail. Further, the present invention is
A second object of the present invention is to provide a receiving mail server that can execute normal deletion processing of electronic mail even if the line is disconnected during acquisition of electronic mail.

[0011]

In order to achieve the above first object, the receiving mail server of the present invention reads a mail from a mailbox according to a request from a client and delivers it to the client. A receiving mail server including a processing unit for executing (POP) processing, wherein when a new mail is stored in the mailbox, at least the identification information of the mail is notified to the client as a destination, Upon receiving from the client a command having a specific message number that causes an error in normal post office protocol (POP) processing and a command with any of the notified identification information as an argument, the processing means , Deliver only mail data corresponding to the argument's identification information to the client It has to so that.

Further, in the receiving mail server of the present invention, when a new mail is stored in the mailbox, the client as the destination of the mail is notified of the attachment information as well as the identification information of the mail. , From the client, a specific message number that causes an error in normal post office protocol (POP) processing, any of the notified identification information, and specification information that specifies either the text or the attached file. When receiving the command with the argument as the argument, the processing means may deliver only the text or the attached file of the designated mail corresponding to the identification information to the client.

Furthermore, the receiving mail server of the present invention which can achieve the above second object, is a post office protocol (POP) process for reading mail from a mailbox and delivering it to the client in response to a request from the client. In the case where the receiving mail server has a processing means for executing the command, the command to delete the mail is received, but the line with the client is disconnected before the termination command is received, before the auto logout timer times out. In addition, when the client makes a re-login request, the processing means deletes the mail designated by the command for deleting the mail from the mailbox by performing a deemed termination process.

Further, when the receiving mail server of the present invention receives a command for deleting a mail, but the line with the client is disconnected before the end command is received, and the auto logout timer times out, The processing unit may delete the mail designated by the command for deleting the mail from the mailbox by performing a deemed termination process.

According to the present invention as described above, from the client, a normal post office protocol (POP) is transmitted.
When receiving a command with a specific message number that causes an error in the processing and one of the notified identification information as an argument, only the mail corresponding to the identification information as an argument is delivered to the client. There is. This allows the client to obtain only the desired email. In addition, a specific message number that causes an error in normal post office protocol (POP) processing, any notified identification information, and specification information that specifies either the text or the attached file are used as arguments. When receiving the command, only the body of the designated mail or the attached file corresponding to the identification information may be delivered to the client. In this case, the client can specify and acquire only the text or the attached file.

Further, according to the present invention, when the client makes a re-login request before the autologout timer times out, the mail designated by the command for performing the deemed termination processing and deleting the mail is deleted from the mailbox. I am trying. Therefore, even if the line is disconnected during the acquisition of the e-mail, the e-mail deletion process can be executed, and the re-login can be enabled before the auto-logout timer times out. Further, when the auto logout timer times out, the mail specified by the command for deleting the mail by performing the deemed end processing is deleted from the mailbox. Therefore, even if the request for re-login is not made, when the line is disconnected during the acquisition of the electronic mail, the deletion processing of the electronic mail can be executed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the outline of the configuration of a mobile communication network including a receiving mail server according to an embodiment of the present invention. The mobile communication network includes the incoming mail server according to the present invention as the extended POP3 server 8. This mobile communication network has a large number of cells, of which only two, cell A and cell B, are shown in FIG. Furthermore, although the nodes making up the mobile communication network are shown, only the nodes associated with cell A and cell B are shown. A base station (BS) 2 is provided in the cell A, and the base station 2 controls communication of the mobile device 1A, which is a mobile communication terminal located in the cell A. In addition, the base station (BS) 3 in cell B
Is provided, and the base station 3 controls the communication of the mobile device 1B, which is a mobile communication terminal located in the cell B.

The base stations 2 and 3 are MSC (Mobi
le Switching Center) 4. MSC4
A is an exchange that relays each exchange of SMSC5, DAS6, PMSC7 and base stations 2, 3, .... GS
N (GPRS (General Packet Radio System) Support
Node) 4B is an exchange that relays the extended POP3 server 8, the SMTP server 9, and the base stations 2, 3, ... By packet exchange, and supports a packet bearer. GPRS is a GSM (global system for mobi).
le packet) based wireless packet system. SMSC (Short Message Servic
The e Center) 5 is an exchange for short messages that supports short message bearers, and when the SMTP server 9 receives a mail, creates a Notification for notifying the arrival of the mail. At this time, if the destination of the mail is the mobile device 1B, the Notification
Is relayed by the SMSC 5 to notify the mobile device 1B via the MSC 4A and the base station 3. The SMTP server 9 is a mail server that transfers mail, and stores mail data sent from other mobile devices and mail data of electronic mail sent from the Internet in a mailbox (Mail B
ox) 10. DAS (Direct Access Syst)
The em) 6 is an exchange that supports a circuit-switched bearer, and can communicate with the mobile station 1B located in the cell B, for example, using the circuit-switched bearer. in this case,
Nodes are mutually connected by the circuit switching bearers in the mobile device 1, the base station 3, the MSC 4A and the DAS 6.

PMSC (Packet Mobile Switching Cent
er) 7 is an exchange that supports a packet bearer, and can perform data communication with the mobile station 1B located in the cell B, for example, using the packet bearer. In this case, the mobile device 1B, the base station 3, the MSC 4A and the PMS
The packet bearer in C7 allows nodes to be connected to each other. SMSC5, DAS6 and PM
The extended POP3 server 8 to which the SC7 is connected is a receiving mail server according to the present invention, and has an extended POP3 protocol that is an extension of POP3. Extended POP
The 3 server 8 delivers the mail data stored in the mailbox 10 to the mobile device 1 when a mail request is made from the mobile devices 1A and 1B using the extended POP3. Expansion P
OP3 is a post office protocol that is an extension of POP3, and as described later, the mobile device 1 that serves as a client.
In A and 1B, it is possible to specify and obtain the desired e-mail of the e-mail addressed to itself, and if the e-mail has an attached file, either the e-mail text or the attached file It is designed so that it can be specified and acquired. The extended POP3 server 8 can be connected to the mobile device 1B via the GSN 4B and the base station 3, and the packet communication network using the GSN 4B can also obtain the electronic mail in the above-described manner.

Next, the extended P according to the embodiment of the present invention.
An example of the configuration of the OP3 server 8 is shown in FIG. In FIG.
The CPU 20 is a central processing unit (Central Processing Unit) that controls the mail delivery processing in the extended POP3 server 8 by executing the extended POP3 program, and the timer 21 indicates the elapsed time during operation or a timer at a specific interval. It is a timer that generates an interrupt. ROM2
Reference numeral 2 denotes a ROM (Read Only Me) in which the extended POP3 program executed by the CPU 20 and various data are stored.
mory). RAM13 is the main memory, CP
RAM (Random A) where the work area of U20 is set
ccess Memory).

The keyboard 24 is provided with a large number of keys for inputting signals such as numbers, characters (katakana, alphabet), symbol keys and function keys.
The display 25 is a display device that displays characters and figures according to the operation of the keyboard 24 and the mouse. The network interface 26 is, for example, an Ethernet (registered trademark) interface, and the network interface 26 allows the SMSC 5, DAS on the network.
6, PMSC 7, and mailbox 10. The HDD 27 is a large-capacity hard disk storage device, and the HDD 27 can store various programs such as an extended POP3 program and data.
When the extended POP3 program is stored in the HDD 27, it is possible to easily upgrade the version of the extended POP3 program. The blocks are connected to each other via a bus 28.

Next, the mail distribution process by the extended POP3 executed by the extended POP3 server 8 according to the present invention will be described with reference to the sequence diagram shown in FIG. As shown in FIG. 3, when the SMTP server 9 receives an electronic mail (Mail), the SMTP server 9 stores the mail in the mailbox 10 and the SMTP server 9 notifies the mail destination that the mail has arrived. , Notification is created and sent to the SMSC 5. In this case, if the destination of the mail is the mobile device 1B, the Notification is notified from the SMSC 5 to the mobile device 1B. This SMS Notification is composed of JUID which is an original unique ID that can newly identify the electronic mail received by SMTP9, JATC which shows the number of attached files, and JATF which is the type information of each attached file. The type information is, for example, an identifier of a file, and when there are a plurality of attached files, JATF-1, JATF-2, ... JA
It is expressed as TF-n.

The mobile device 1B receives this Notification,
When the mobile device 1B receives the notified request to acquire the electronic mail from the user, the mobile device 1B establishes a TCP (Transmission Control Protocol) connection with the extended POP3 server 8 using the TCP port of the port number 110. Then, the login sequence of POP3 is performed. This login sequence authenticates the user. When the user is authenticated in the login sequence, the POP session goes into a transaction state. Here, as shown in FIG. 3, the mobile device 1B uses the first argument of the message number 0 and the JUID notified by Notification to obtain the e-mail notified by Notification stored in the mailbox 10. Extended POP3 with RETR command ("RETR 0, JUID") with 2 arguments
Send to server 8. The extended POP3 server 8 uses this R
When it receives the ETR command, it sends a positive response "+ OK" to the mobile device 1B. Further, since the first argument of the RETR command is "0", the mail data of the electronic mail specified by the JUID of the second argument is transmitted to the mobile device 1B. When an attachment file is attached to this e-mail, the mail data consists of the text and the attachment file.

When the mobile device 1B receives the mail data,
The mobile device 1B sends a DELE command for deleting the electronic mail to the extended POP3 server 8. The argument of this DELE command corresponds to the delivered mail data, the first argument is the message number 0, and the second argument is Notifica.
It will be the JUID notified by option. First argument 0, second
The extended POP3 server 8, which has received the DELE command (“DELE 0, JUID”) of the argument JUID, sets a deletion flag for the mail data to delete the mail data specified by the JUID notified by Notification. An affirmative response "+ OK" is transmitted to the mobile device 1B. Positive response "+ O
The mobile device 1B which has received the K "is sent to the end command QU.
The IT command is transmitted to the extended POP3 server 8. As a result, the session shifts to the update state and the QUI
Upon receiving the T command, the extended POP3 server 8 deletes the mail data flagged for deletion from the mailbox,
An affirmative response "+ OK" is transmitted to the mobile device 1B. This will log off POP3 and close the TCP connection. Note that any message can be added to the positive response "+ OK", which means "any string".
s ".

By the way, an extended POP is provided on the network.
Not only three servers but also POP3 servers exist. Here, it is assumed that the RETR command of "RETR 0, JUID" is erroneously transmitted to the POP3 server that does not support the extended POP3. When the POP3 server receives a RETR command in which the message number argument is "0",
In No. 3, since the message number is defined to start from "1", a negative response "-ERR" is returned. Therefore, the unique I of POP3 that matches the second argument JUID
Even if the UID D is accidentally present, the mail data is not read and delivered. Also, PO
The same is true when the P3 server receives a DELE command of "DELE 0, JUID", and returns a negative response "-ERR". Therefore, even if a UID that coincides with the second argument JUID happens to exist, the mail data is not deleted. As described above, according to the receiving mail server of the present invention, it is possible to acquire only the mail data of a desired electronic mail without adversely affecting the POP3 server.

Further, in the mail distribution process by the extended POP3, when the mail data is composed of the text and the attached file, only the text or one of the attached files can be acquired. Hereinafter, description will be given with reference to the sequence diagram shown in FIG. In the sequence shown in FIG. 4, the sequence up to the login sequence of POP3 is the same as the sequence shown in FIG. 3, so description thereof will be omitted. When the POP session is in the transaction state, the mobile device 1B acquires the e-mail notified by the Notification stored in the mailbox 10 as shown in FIG. JUID and extension ID notified by Notification
(ExtID) and the second argument is the RETR command ("RETR
0, JUID.ExtID ") to the extended POP3 server 8.

The extension ID will be described with an example. Here, it is assumed that JATC = 2 is notified by Notification and the number of attached files is 2, and the first attached file is image data that is JPEG-compressed by notifying that JATF-1 = jpeg, and the second attached file is Attachment is JATF
It is assumed that the image data is GIF-compressed after being notified that -2 = gif. User sees Notification and sees JPEG
If you decide that you want to get only the first attached file because it is compressed image data, "RETR0, JUID.
Send the RETR command as 01 ". This RETR
"01" in the command specifies JATF-1. If "00" is replaced with "01", the text is designated, and if "01" is replaced with "02", the JATF is specified.
-2 is specified.

The extended POP3 server 8 uses such RE
Receiving an affirmative response “+ OK” when receiving the TR command, mobile unit 1
Send to B. Further, since the first argument of the RETR command is “0”, only the mail data portion specified by the extended ID in the mail data of the electronic mail specified by the second argument JUID is transferred to the mobile device. Send to 1B. For example, when the RETR command is "RETR 0, JUID.01", only the file data of the first attached file JATF-1 is delivered to the mobile device 1B. Mobile device 1B
When the mobile device 1B receives the mail data, the mobile device 1B sends a DELE command for deleting the electronic mail to the extended POP3 server 8. The arguments of this DELE command correspond to the delivered mail data, and the first argument of the message number 0, the JUID and the extension ID notified by Notification.
(ExtID) is used as the second argument. The extended POP3 server 8 that has received this DELE command ("DELE 0, JUID.01") sets a deletion flag to the corresponding file of the mail data in order to delete the file of the mail data specified by the second argument. Stand up and give positive response "+ OK" to mobile unit 1
Send to B.

Mobile unit 1B which received the positive response "+ OK"
Ends the QUIT command, which is an end command, with an extended POP
3 Send to server 8. As a result, the session is updated and the extended PO that received the QUIT command
The P3 server 8 logically deletes the mail data for which the deletion flag is set from the mailbox 10, and an affirmative response “+ OK”
Is transmitted to the mobile device 1B. This will log off POP3 and close the TCP connection. here,
Logical deletion corresponds to partial deletion of mail data, and when all parts of mail data are logically deleted, the mail data is physically deleted. However, MIM
If partial physical deletion is possible without changing the E (Multipurpose Internet Mail Extensions) structure,
Partial physical deletion is performed instead of partial logical deletion. Note that the RETR command of "RETR 0, JUID.01" and the DELE command of "DELE 0, JUID.01" are mistakenly
Even if the OP3 server receives the negative response “-” as described above.
Since it simply returns "ERR", the mail data is not erroneously delivered or deleted later. As described above, according to the receiving mail server of the present invention, an electronic mail can be constructed without adversely affecting the POP3 server. You will be able to retrieve only the body text or one of the attached files.

Next, the mobile device 1B is operated by the expanded POP3 server 8
When the mobile device 1B moves into a tunnel or the like while getting an e-mail from the squelch disconnection or moves out of the service area and is disconnected, the mail distribution process by the extended POP3 is performed as shown in FIG. This will be described with reference to the sequence diagram shown in FIG. It is assumed that, after some sequence is performed as shown in FIG. 5, the extended POP3 server 8 is notified of the DELE command having the first argument 0 and the second argument JUID. In this case, the extended POP3 server 8 sets the deletion flag for the mail data specified by the second argument JUID and activates the auto logout timer.

Here, it is assumed that the squelch is disconnected or the wireless communication line is disconnected due to out-of-service. Then, it is assumed that the user makes a login request for POP3 again, knowing that the user has been disconnected. In this login request, the mobile device 1B transmits to the extended POP3 server 8 a USER command with the user name username given for authentication as an argument.
In this case, although the auto logout timer is started, the extended POP3 server 8 accepts the USER command because it is in the transaction state, and the Q
Assuming that the UIT command has been received, the state is shifted to the update state, and the deemed QUIT process is performed. That is, the second
The mail data flagged in the session before being specified by the argument JUID will be deleted. Then, the positive response “+ OK” is transmitted to the mobile device 1B. After this, normal login processing is performed. In this way, even if the wireless line is disconnected before the deletion of the specified mail data is completed, the specified POP3 server 8 will delete the specified mail data when the user logs in again, and the session will be normally executed. It will be treated as if it had ended. Further, re-access may be enabled before the autologout timer times out.

Next, the mobile device 1B is operated by the extended POP3 server 8
By the expansion POP3 when the auto logout timer times out when the mobile device 1B moves into a tunnel or the like and disconnects from the squelch while receiving an email from The mail delivery process will be described with reference to the sequence diagram shown in FIG. It is assumed that, after some sequence is performed as shown in FIG. 6, the extended POP3 server 8 is notified of the DELE command having the first argument 0 and the second argument JUID. In this case, the extended POP3 server 8 sets the deletion flag for the mail data specified by the second argument JUID and activates the auto logout timer.

Here, it is assumed that the squelch is cut off or the service area is out of service and the wireless line is disconnected. Then, it is assumed that the auto logout timer times out without the mobile device 1B requesting the login of POP3 again. In this case, it is assumed that the QUIT command has been received from the transaction state and the state is changed to the update state.
Perform processing. That is, the mail data flagged in the session before being specified by the second argument JUID will be deleted. Then, positive response "+ OK"
Is transmitted to the mobile device 1B. In this way, even if the wireless line is disconnected before the deletion of the specified mail data is completed,
In the extended POP3 server 8, the designated mail data will be deleted when the auto logout timer times out, and will be treated as if the session ended normally.

[0034]

As described above, the present invention allows a client to send a message to a normal post office protocol (PO).
P) When receiving a command with a specific message number that causes an error in the processing and one of the notified identification information as an argument, deliver only the mail corresponding to the identified identification information to the client. I have to. This allows the client to obtain only the desired email. Furthermore, a specific message number that causes an error in normal post office protocol (POP) processing, and any identification information notified,
When receiving a command with the specified information that specifies either the body text or the attachment file as an argument, only the body text or the attachment file of the specified mail corresponding to the identification information is delivered to the client. You may In this case, the client can specify and acquire only the text or the attached file.

Further, according to the present invention, if the client makes a re-login request before the autologout timer times out, the mail designated by the command for performing the deemed termination processing and deleting the mail is deleted from the mailbox. I am trying. Therefore, even if the line is disconnected during the acquisition of the e-mail, the e-mail deletion process can be executed, and the re-login can be enabled before the auto-logout timer times out. Further, when the auto logout timer times out, the mail specified by the command for deleting the mail by performing the deemed end processing is deleted from the mailbox. Therefore, even if the request for re-login is not made, when the line is disconnected during the acquisition of the electronic mail, the deletion processing of the electronic mail can be executed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a configuration of a mobile communication network including a receiving mail server according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a reception mail server according to the exemplary embodiment of the present invention.

FIG. 3 is a sequence diagram showing a mail delivery process executed by the receiving mail server according to the embodiment of the present invention.

FIG. 4 is a sequence diagram showing a mail delivery process executed by the incoming mail server according to the embodiment of the present invention.

FIG. 5 is a sequence diagram showing a mail delivery process executed by the receiving mail server according to the embodiment of the present invention when the line is disconnected.

FIG. 6 is a sequence diagram showing a mail delivery process executed by the receiving mail server according to the embodiment of the present invention when the line is disconnected.

FIG. 7 is a sequence diagram showing mail delivery processing executed by the POP3 server.

FIG. 8 is a sequence diagram showing a mail delivery process executed by the POP3 server when the line is disconnected.

FIG. 9 is a sequence diagram showing a mail delivery process executed by the POP3 server when the line is disconnected.

[Explanation of symbols]

1A mobile, 1B mobile, 2, 3, base station, 4A
MSC, 4B GSN, 5 SMSC, 6 DAS,
7 PMSC, 8 extended POP3 server, 9 SMTP
Server, 10 mailbox, 20 CPU, 21
Timer, 22 ROM, 23 RAM, 24 keyboard, 25 display, 26 network interface, 27 HDD, 28 bus

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinichi Akahoshi             34 Shinanomachi Shinjuku-ku, Tokyo JR Shinanomachi Bi             Within Le JF East Japan Co., Ltd. (72) Inventor Hiroshi Kanegae             34 Shinanomachi Shinjuku-ku, Tokyo JR Shinanomachi Bi             Within Le JF East Japan Co., Ltd. (72) Inventor Masahiro Oda             34 Shinanomachi Shinjuku-ku, Tokyo JR Shinanomachi Bi             Within Le JF East Japan Co., Ltd. F term (reference) 5K030 HA06 KA01 KA06 LA00

Claims (4)

[Claims] 1. A receiving mail server comprising processing means for executing post office protocol (POP) processing for reading mail from a mailbox and delivering the mail to the client in response to a request from the client. When a lot of emails are accumulated,
At least the identification information of the mail has been notified to the destination client, and the specific message number that causes an error in the normal post office protocol (POP) processing from the client, and one of the notified ones. The receiving mail server, wherein when the command having the identification information as an argument is received, the processing means delivers only the mail data corresponding to the identification information as the argument to the client. 2. When a new mail is stored in the mailbox, the client, which is the destination of the mail, is notified of the attached file information in addition to the identification information of the mail. A command with an argument of a specific message number that causes an error in office protocol (POP) processing, any of the notified identification information, and specification information that specifies either the text or the attached file is received. The receiving mail server according to claim 1, wherein the processing means is configured to deliver only the text or an attached file of the designated mail corresponding to the identification information to the client. 3. A reception mail server comprising processing means for executing post office protocol (POP) processing for reading a mail from a mailbox and delivering the mail to the client in response to a request from the client, wherein the command deletes the mail. However, in the case where the line with the client is disconnected before receiving the end command, the client makes a re-login request before the autologout timer times out, the processing means, A receiving mail server, characterized in that a mail designated by a command for deleting the mail by performing a deemed termination process is deleted from the mailbox. 4. When a command for deleting a mail is received, but the line with the client is disconnected before the end command is received and the auto logout timer times out, the processing means performs the deemed end processing. 4. The receiving mail server according to claim 3, wherein a mail designated by a command for deleting the mail is deleted from the mailbox.