JP2005033659A - Mail server device and information communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide data of an appropriate format corresponding to the capabilities of an information communication terminal device. <P>SOLUTION: When a receiving part 21 receives a message, a message analytic part 22 decides the format of a data file attached to this message. A file format converting part 24 refers to the user terminal capability holding part 23 to decide whether or not the format of the data file decided by the message analytic part 22 is available in a portable telephone terminal device 40 and when that format is not available, the relevant data file is converted into an available format. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mail server device and an information communication system that can provide a data file in a format corresponding to the capability of an information communication terminal device.

  SMTP, POP3, and IMAP4 are known as protocols for transmitting and receiving messages on a network using TCP / IP such as the Internet (for example, see Non-Patent Document 1 and Non-Patent Document 2 and Non-Patent Document 3). E-mail services according to these protocols are widely used.

In such an e-mail service, a data file encoded in a multipart MIME (Multipurpose Internet Mail Extension) format can be attached (for example, see Non-Patent Documents 4 to 8).
Jonathan B. Postel, "RFC-821", [online], August 1982, [Searched on December 31, 2002], Internet <URL: http://www.ietf.org/rfc/rfc0821.txt >, P. 2-5 J. Myers, M. Rose, "RFC-1939", [online], May 1996, [Searched on December 31, 2002], Internet <URL: http://www.ietf.org/rfc/ rfc1939.txt>, p. 2-4 M. Crispin, “RFC-2060”, [online], December 1996, [searched on January 1, 2003], Internet <URL: http://www.ietf.org/rfc/rfc2060.txt> , P. 4-79 N. Freed, N. Borenstein, “RFC2045”, [online], November 1996, [searched on June 1, 2003], Internet <URL: http://www.ietf.org/rfc/rfc2045. txt>, p. 3-31 N. Freed, N. Borenstein, RFC 2046 ", [online], November 1996, [searched on June 1, 2003], Internet <URL: http://www.ietf.org/rfc/rfc2046.txt >, P. 3-44 K. Moore, RFC 2047 ", [online], November 1996, [searched on June 1, 2003], Internet <URL: http://www.ietf.org/rfc/rfc2047.txt>, p. 1-13 N. Freed, J. Klensin, J. Postel, RFC 2048 ", [online], November 1996, [searched on June 1, 2003], Internet <URL: http://www.ietf.org/rfc /rfc2048.txt>, p. 1-21 N. Freed, N. Borenstein, RFC 2049 ", [online], November 1996, [Search June 1, 2003], Internet <URL: http://www.ietf.org/rfc/rfc2049.txt >, P. 1-24

  However, restrictions on display capability, storage capacity, and the like of information communication terminal devices such as mobile phone terminal devices may differ from model to model. If data of the same file format (including resolution, etc.) is uniformly supplied to information communication terminal devices with different restriction conditions, they may not be received or displayed.

  The present invention has been made in view of the above problems, and provides a mail server device and an information communication system that can provide data in an appropriate format according to the capability of the information communication terminal device. Objective.

  In order to solve the above-described problem, a mail server device according to the present invention includes a terminal capability holding unit that holds information indicating a data file format that can be used in an information communication terminal device to which an electronic mail service is provided, and a reception Referring to the format detection means for detecting the format of the data file attached to the received message (received message) and the terminal capability holding means, the format of the data file detected by the format detection means is attached to the data file. A determination unit that determines whether or not the format is usable in the information communication terminal device corresponding to the destination of the received message, and a format in which the data file can be used in the information communication terminal device according to the determination result of the determination unit If the data file is not, the data file is transferred to the information utilization terminal device. Characterized in that it comprises a conversion control means for converting the available formats Te.

  The information communication system according to the present invention includes the mail server device according to the present invention.

  In the present invention, when the format of the data file detected by the format detection unit is not a format that can be used in the information communication terminal device corresponding to the destination of the received message to which the data file is attached, the conversion control unit Further, by converting the data file into a format that can be used by the information using terminal device, it is possible to provide data in an appropriate format according to the capability of the information communication terminal device that is the destination of the message.

  The present invention can be applied to an information communication system that provides services such as an electronic mail service and an HTTP (Hyper Text Transfer Protocol) service to an information use terminal device such as a mobile phone terminal device.

(Constitution)
An information communication system according to an embodiment of the present invention includes, for example, a mail server 20 that provides a mail service and a mobile that uses the mail service provided by the mail server 20 via a mobile communication network 30, as shown in FIG. Phone terminal device 40.

  In the mbox 10, user areas 11, 12,... are provided for each user account, and messages 11a, 11b,... are stored in these user areas 11, 12,. It is like that.

  The mail server 20 receives a message supplied via the network 1 such as the Internet according to a protocol such as SMTP, stores it in the mbox 10, and addresses the mail address of the user of the mobile phone terminal device 40 according to the protocol such as POP3 or IMAP4. Provide a message. The mail server 20 includes a receiving unit 21 that receives a message supplied via the network 1 and stores the message in the mbox 10, a message analyzing unit 22 that analyzes a structure of the message received by the receiving unit 21, and a mobile phone A user terminal capability holding unit 23 for holding information indicating the display capability and the like of the terminal device 40, a file format conversion unit 24 for converting the format of the data file attached to the message analyzed by the message analysis unit 22, and a new A notification unit 25 that transmits a reception notification indicating that a message has been received to the mobile phone terminal device 40; and a message providing unit 26 that provides a message stored in the mbox 10 in response to a request from the mobile phone terminal device 40. I have.

  The mobile communication network 30 includes a circuit switch 31 that performs processing such as radio channel assignment with the mobile phone terminal device 40, a packet switch 32 that performs processing for exchanging packet data for data communication, and the like, for example, 140 octets. A short message service center (SMSC) 33 that provides a short message (short message) to the mobile phone terminal device 40 and a base station device (BS: wireless communication) between the mobile phone terminal device 40 Base station) 35a, 35b,..., 35n, base station controller (BSC) 34 that manages BS 35a to 35n, and subscriber location registration that manages registration information and the like of mobile phone terminal 40 And a device (HLR: Home Location Register) 39.

  The mobile phone terminal device 40 can use a call service, an HTTP service, and the like via the mobile communication network 30 and a mail service provided by the mail server 20. This mobile phone terminal device 40 performs a display to the user, a radio frequency (RF) unit 41 for processing a high frequency signal, an MPU 42, a memory 43, an operation key 44 for inputting an instruction from the user, and the like. A display unit 45, an audio CODEC 46 that encodes / decodes an audio signal, an MIC 47, and a speaker 48 are provided.

  The MPU 42 executes, for example, a control program held in the memory 43, thereby controlling the communication control unit 50 that controls communication via the mobile communication network 30, an e-mail client 60 that transmits and receives e-mail, and e-mail It functions as a browser 70 that displays the message. The e-mail client 60 includes a normal mail processing unit 61 that uses a mail service provided by the mail server 20 and an SMS processing unit 62 that uses a short message service provided by the SMSC 33. The memory 43 also includes a setting holding unit 43a that holds setting information and a message holding unit 43b that holds messages.

(Message example)
As shown in FIG. 2, for example, the message transmitted / received by the mail server 20 to / from the network 1 side includes a message transmission route, transmission date / time, sender (From field), destination (To field), subject (Subject field), and message. The header 301 includes information such as an ID, and a body 302. The body 302 may be further composed of a MIME multipart message. In the example of FIG. 2, the body 302 is composed of a body text part 302a and an attached file (Test.png) 302b. Yes.

  By the way, in this information communication system, the upper limit size of one message received by the e-mail client 60 is limited to, for example, 140 octets for a short message and 30 kbytes including a header for a normal message.

  On the other hand, the message received by the mail server 20 is supplied from the network 1 side in addition to the mobile phone terminal device 40, and is a size equal to or larger than the short message or the upper limit size of the message in the e-mail client 60. In some cases.

  For this reason, in this information communication system, when the mail server 20 receives a message addressed to the mobile phone terminal device 40, first, a part of the header and the body text (when the size limit in the short message is exceeded) The above-mentioned reception notification including the presence / absence and type of attached file is transmitted to the mobile phone terminal device 40.

  For example, if there is no attached file in the message and the size of the body text is within the size limit, the e-mail client 60 does not request the mail server 20 to send the message further. However, if there is an attached file or if the size of the body text is larger than the size limit, the e-mail client 60 sends the attached file or body text (remaining specified size) to the mail server 20 in accordance with an instruction from the user. (Only minutes).

(Attachment file format conversion)
By the way, the message received by the mail server 20 from the network 1 side may be accompanied by a data file in a format that cannot be reproduced on the mobile phone terminal device 40 side of the message destination.

  The display capability of the display unit 45 of the mobile phone terminal device 40 is limited in the number of display pixels or the number of display colors compared to the display unit of a general-purpose information processing device such as a personal computer. For this reason, even a data file of an image that can be displayed by a general-purpose information processing device may not be displayed by the mobile phone terminal device 40. In addition, there are cases where it is impossible to reproduce or display a voice data file or a data file in a format depending on the application on the mobile phone terminal device 40 side.

  Furthermore, the display capability may differ depending on the model of the mobile phone terminal device 40, and even a data file that can be displayed on one mobile phone terminal device 40 may not be displayed on another mobile phone terminal device 40. In addition, there may be a case where the specifications of the mobile phone terminal device 40 are different depending on the shipping time, the type of service that can be used, and the like, and it is necessary to individually manage the display capability.

  Therefore, in this information communication system, the mail server 20 confirms the format of the data file attached to the message, and if the format cannot be displayed on the mobile phone terminal device 40, the mobile phone terminal device 40 The information is converted into a displayable format and provided to the mobile phone terminal device 40.

  Specifically, for example, as shown in FIG. 3, the user terminal capability holding unit 23 is provided with an address that is a message destination and attribute information (model ID) indicating the model of the mobile phone terminal device 40 corresponding to the address. An address table 23a to be held and a terminal table 23b to hold the capability of the mobile phone terminal device 40 corresponding to the model ID are provided. The file format conversion unit 24 can acquire the model ID from the address table 23a using the address as a key, and can acquire the capability of the mobile phone terminal device 40 corresponding to the address from the terminal table 23b using the model ID as a key. It has become.

  The format of the data file attached to the message is based on the MIME type in the body 302 and the extension in the file name (name field, filename field if no name field exists) in each part, for example, FIG. It can be specified by referring to the extension conversion table shown in FIG. The message analysis unit 22 holds this extension conversion table.

  Further, for example, as shown in FIG. 5, the file format conversion unit 24 includes an image format conversion unit 24 a that converts the format of the image data file, an audio format conversion unit 24 b that converts the format of the audio data file, The format conversion unit 24c that converts the format of the data file depending on the application, the format of the data file detected by the message analysis unit 22, and the destination of the message to which the data file acquired from the user terminal capability holding unit 23 is attached And a control unit 22d for controlling the operation of each of the format conversion units 24a to 24c according to the capability of the mobile phone terminal device 40.

  Each format conversion unit 24a to 24c includes a conversion unit (conversion unit A, conversion unit B, conversion unit C,...) Using a known program for executing a specific data file conversion process. According to the control from the control unit 24d, the data file format is converted by a predetermined conversion unit. The conversion unit is modularized, and by adding a conversion unit, it is possible to cope with future file formats.

(Operation)
In the information communication system configured as described above, when the receiving unit 21 of the mail server 20 receives a message, for example, in S0 in FIG. 6, the receiving unit 21 notifies the file format converting unit 24 that the message has been received. Then, the file format conversion unit 24 inquires of the user terminal capability holding unit 23 about the capability of the mobile phone terminal device 40 that is the destination of the message (S1).

  When there is an answer from the user terminal capability holding unit 23 (S2), the file format conversion unit 24 sends the format of the data file attached to the message obtained from the message analysis result by the message analysis unit 22 and the mobile phone. The terminal device 40 is compared with the capability, and if the display or the like is not possible on the mobile phone terminal device 40, the data file format is converted, and the converted data file is stored in the user area 11 of the user of the mbox 10. (S3).

  When the conversion of the data file format is completed, the file format conversion unit 24 instructs the notification unit 25 to transmit a reception notification notifying the mobile phone terminal device 40 that a new message has been received (S4). . This reception notification is supplied to the SMS processing unit 62 of the mobile phone terminal device 40 via the SMSC 33 or the like (S5).

  For example, as shown in FIG. 7, the information notified in this reception notification is information indicating the presence or absence of subsequent information such as a transmission source address, a subject, a part of a text, and a text in a conventional information communication system of the same type. However, in this information communication system, for example, a reply address (Reply-to field), information indicating the structure of a message instead of information indicating the presence / absence of subsequent information such as a text, and information on an attached file are used. Yes.

  When the reception notification as described above is received, the SMS processing unit 62 responds to the received reception notification, for example, as shown in FIG. 8A, information on the source address, subject, message structure, and attached file. Etc. are displayed on the display unit 45 (S6). In response to this, when the user operates the operation key 44 to instruct a part (header, text, attached file) desired to be received, the normal mail processing unit 61 issues a command (message request) that requests transmission of the instructed part. ) Is transmitted to the message provider 26 of the mail server 20 (S7). In response to this message request, the message providing unit 26 acquires the instructed part from the mbox 10 and transmits it to the mobile phone terminal device 40. As a result, the attachment file desired by the user is supplied to the normal mail processing unit 61.

(Operation details)
In the determination process of the data file format in the message analysis of S3 described above, the message analysis unit 22 first analyzes the MIME structure of the message and executes the format determination process for each part.

  In this determination process, the message analysis unit 22 uses, for example, the content-type field (S101, S103, S109) and the file name (S111 to S120) of each part as shown in FIGS. 9-1 and 9-2. The data file format is determined.

  Specifically, first, it is determined whether or not the Content-type is “message / rfc 822” (S101), and if applicable, the part is electronic in the notification extension (Atype in FIG. 4) of the part. “822” indicating the mail file is set (S102).

  Next, it is confirmed whether or not the Content-type is “text / plain” (S103). If applicable, whether or not “name” exists in the Content-type or “filename” in the Content-Disposition. "Is present or not (S104). If it exists, it is checked whether or not it is the first part that matches the condition (S105). If it is the first part that matches, the message body is used and the part is treated as an attached file. Otherwise (S106), otherwise, "BDY" is set in the notification extension (Type) (S108). If “name” does not exist in the Content-type or “filename” does not exist in the Content-Disposition, “TXT” is set in the notification extension (Type) (S107).

  If the content-type is not “text / plain”, it is checked whether or not the content-type is “text / html” (S109). If applicable, the notification extension (type) is set to “HTM”. "Is set (S110).

  If the content-type is not “text / html”, it is checked whether “name” exists in the content-type or whether “filename” exists in the content-disposition (S111). In this case, if the file name is encoded (S112), it is confirmed whether or not the file name is normal when it is decoded (S113). Is set (S114).

  If the file name is not encoded or the decoded result of the encoded file name is normal, the Content-type is “image / mt * (* is an arbitrary character string)” and the name field Alternatively, it is confirmed whether or not the extension of the file name in the filename field is JPG or PNG (S115). When one of these extensions is applicable, the extension of the file name corresponds to one of “mt?” (? Is the letter “n” or one-digit numbers “2” to “9”). (S116), if applicable, “mt?” (? Is the value determined in S116) is set in the notification extension (Type) (S117).

  If the extension of the content-type and the file name does not match the above-mentioned conditions, it is confirmed whether or not the extension of the file name exists in the above-described extension conversion table shown in FIG. 4 (S118). If so, a notification extension (Type) corresponding to the extension is selected from the extension conversion table and set (S119). If the extension of the file name does not exist in the extension conversion table, “???” is set as the notification extension (Type) (S120).

  In addition, when “name” does not exist in the Content-type or when “filename” does not exist in the Content-Disposition, it is considered that there is no file name in the part, and even if it is supplied to the mobile phone terminal device 40 It cannot be displayed. In such a case, the notification unit 24 is instructed not to include the attached file information in the reception notification, and the message providing unit 26 does not include the attached file information in the response S8 to the request S7 from the mobile phone terminal device 40. (S121).

  The message analysis unit 22 notifies the file format conversion unit 24 of the notification extension (Type) set as described above as information indicating the format of the file.

  Incidentally, as described above, the message providing unit 26 can provide a message to the mobile phone terminal device 40 for each part. The message providing unit 26 performs processing such as reading a message on the mbox 10 in a procedure according to, for example, IMAP4.

  On the other hand, due to limitations on the processing performance of the MPU 42, the IMAP 4 itself is not implemented in the normal mail processing unit 61, and the message transmission request is assigned to a command requesting message transmission and individual messages. Identification information (UID: Unique ID) and information indicating a part to be a transmission request [for example, a part number such as “2.1” according to the MIME structure] are designated.

  The message providing unit 26 internally generates an IMAP command in response to such a transmission request and performs an operation on the mbox 10. Specifically, for example, as illustrated in FIG. 10, the message providing unit 26 transmits and receives a command to and from the mobile phone terminal device 40, and a request to analyze a request from the mobile phone terminal device 40. An analysis unit 26b, a message acquisition unit 26c that acquires a message from the mbox 10, and a response configuration unit 26d that forms a response message to the mobile phone terminal device 40 are provided.

  The request analysis unit 26b of the message providing unit 26 internally analyzes the command and parameters (UID, part number, etc.) in the transmission request supplied from the normal mail processing unit 61 and internally generates an IMAP command corresponding to the transmission request. The message acquisition unit 26c is instructed to acquire the data of the specified part of the message specified from the mbox 10. When the message acquisition unit 26c acquires data from the mbox 10, the message acquisition unit 26c instructs the message analysis unit 22 to analyze the acquired message, and if necessary, causes the file format conversion unit 24 to convert the file format, and instructs the response configuration unit 26d. Then, a response message corresponding to the response of the IMAP4 server 21 is generated and transmitted to the normal mail processing unit 61 via the transmission / reception unit 26a. With this operation, this information communication system can perform processing such as reception, transfer, and deletion for each part of a message even if the IMAP4 protocol is not implemented on the mobile phone terminal device 40 side. ing.

(effect)
As described above, in this information communication system, the format of the data file attached to the message is changed to the mobile phone terminal device according to the capability of the mobile phone terminal device 40 held in the user terminal capability holding unit 23. It can be converted into a reproducible format according to 40 capabilities.

  For this reason, the possibility that the data file can be reproduced on the mobile phone terminal device 40 side is increased, and the necessity of an operation such as transferring to another address when the data file cannot be reproduced on the mobile phone terminal device 40 side is reduced. Can do. Therefore, it is possible to contribute to reduction of useless traffic. By reducing unnecessary traffic, it is possible to contribute to a reduction in communication cost burden on the user side.

  Further, in this information communication system, even when the format and extension of a new data file increase, the above-described extension conversion table held by the message analysis unit 22 is changed, and the conversion process in the file format conversion unit 24 is performed. By adjusting the selection, the data file attached to the message can be converted into an appropriate format. Therefore, it is possible to easily cope with an increase in the format of the data file.

  Furthermore, in this information communication system, since the reception notification includes information that can individually specify the attached file, the user can select only the reception of the required attached file, which contributes to the reduction of unnecessary traffic. can do. In addition, since the attached file that can be requested from the mobile phone terminal device 40 has been converted into a format that can be played by the mobile phone terminal device 40 as described above, it cannot be understood that it cannot be played back until it is received. Generation can be reduced.

(Modification 1)
Further, for example, the mail server 20 may check whether the content of the data file attached to the message is valid according to the extension or the file format. For example, based on the header information of the file, it is confirmed whether or not the image file can be normally displayed and whether or not the sound file can be normally reproduced. Thereby, for example, the possibility that the mobile phone terminal device 40 malfunctions due to a data file having an inappropriate extension or file format can be reduced.

(Modification 2)
Further, for example, in the terminal table 23b shown in FIG. 3 described above, only the model ID is managed, but the specification may be slightly different for each version of the model. Therefore, the capability may be managed for each version of the mobile phone terminal device 40 in the terminal table 23b. This makes it possible to manage the capabilities of different versions of the same model.

(Modification 3)
By the way, in the above-mentioned embodiment, as described above, the format of the data file attached to the message is uniformly converted for each model for each model ID, but for example, for each mobile phone terminal device 40 You may make it convert into the format which a user desires.

  For this purpose, the user terminal capability holding unit 23 is provided with a table for holding a desired format for each address, for example, as shown in FIG. 11, and the format desired by the user is registered in advance. The file format conversion unit 24 converts the format of the data file attached for each destination address of the message. Thus, for example, if the user sets the format so that the size of the data file is reduced, the amount of data to be received can be reduced.

  In order to reduce the size of the still image data file, for example, the screen size is reduced (FIG. 12), the color is reduced (FIG. 13), the compression rate of the image format is increased, that is, the image quality is deteriorated (FIG. 14), etc. There is a way. In order to reduce the size of the audio data file, the conversion from stereo to monaural (FIG. 15), the sampling rate is lowered (FIG. 16), the compression rate of the audio format is increased, that is, the sound quality is deteriorated, etc. There is a way. Alternatively, a moving image may be divided into a plurality of still images and audio, or conversion between different still image formats, conversion between different moving image formats, or conversion between different audio formats may be performed.

  In order to realize such an operation, for example, a web server capable of holding the information of FIG. 11 in the user terminal capability holding unit 23 and changing the information of FIG. 11 for each user is provided. This web server is connected to the user terminal capability holding unit 23, can be accessed from the browser 70 in the mobile phone terminal device 40, and changes the information in FIG. 11 in accordance with an instruction from the user.

(Modification 4)
In the above description of the embodiment, a digital mobile communication network such as a PDC (Personal Digital Cellular) system has been assumed. However, as shown in FIG. 17, for example, a third generation digital mobile such as a W-CDMA system is used. The present invention can also be applied to a body communication network.

  In the PDC system, the mobile phone terminal device 40 has a one-to-one correspondence with the address, so that the capability (manufacturer, device type, device specification, etc.) of the mobile phone terminal device 40 is determined from the address as in the above-described embodiment. I was able to know.

  However, in the third generation digital mobile communication network, the subscriber identifier (USIM) 99 and the mobile phone terminal (UE) 90 are configured to be separable, and the user can use the subscriber identifier (USIM) 99 and the mobile phone. The terminal device (UE) 90 can be freely combined.

  For this reason, the third generation digital mobile communication network requires means for acquiring information (IMEI) of the mobile phone terminal device (UE) 90 when connected to the mobile communication network in real time. There are several possible schemes, but the information communication terminal device is referred to the HLR (subscriber location registration) 89 before notifying the information communication terminal device (UE) 90 of the mail file and the attached file information attached to the message. A method for specifying the capability (manufacturer, device type, device specification) of (UE) 90 is conceivable.

  For example, the user ID (IMSI, 3GPP TS29.002 (R99) in the subscriber identifier (USIM) 99, http://www.3gpp.org/ftp/Specs/1999-12/23_series/23003-330.zip In addition to the information of the terminal telephone terminal device (UE) 90 (IMEI, 3GPP TS22.016 (R99), http://www.3gpp.org/ftp/Specs/1999-12/22_series/22016-310. zip reference) is notified to the HLR 89, and the user terminal capability holding unit 23 'uses the common channel signaling system (MAP) protocol (3GPP TS29.002 (R99), http: // www) .3gpp.org / ftp / Specs / 1999-12 / 29_series / 29002-332.zip)

  In addition, as shown in FIG. 18, the user terminal capability holding unit 23 ′ includes a table 23 a ′ indicating correspondence between addresses and user IDs (IMSI), information (IMEI) and capability of the mobile phone terminal device (UE) 90. A table 23b ′ showing the correspondence between the two is provided.

  The file format conversion unit 24 refers to the table 23 a ′, acquires the user ID (ISMI) corresponding to the message destination, and acquires the IMEI corresponding to the acquired ISMI from the HLR 89. Further, the file format conversion unit 24 refers to the table 23 b ′ and acquires information indicating the capability of the mobile phone terminal device 90 corresponding to the IMEI acquired from the HLR 89.

  By using the acquired information indicating the capability of the mobile phone terminal device 90, the data file attached to the message is converted into a format corresponding to the capability of the mobile phone terminal device 40 and provided, as in the above-described embodiment. can do.

It is a figure which shows the structural example of the information communication system which concerns on one Example of this invention. It is a figure which shows the example of the message transmitted with the said information communication system. It is a figure which shows an example of the table hold | maintained at the user terminal capability holding | maintenance part of the mail server which comprises the said information communication system. It is a figure which shows an example of a conversion table. It is a figure which shows the structural example of a file format conversion part. FIG. 11 is a sequence diagram illustrating an example of message reception notification and message supply processing to the mobile phone terminal device. It is a figure which shows an example of the information notified by reception notification. It is a figure which shows an example of the image displayed on the display part of a mobile telephone terminal device. It is a flowchart which shows an example of a file format determination process. It is a flowchart which shows an example of a file format determination process. It is a figure which shows the structural example of a message provision part. It is a figure which shows an example of the information added to the table hold | maintained at a user terminal capability holding | maintenance part. It is a figure which shows an example of the reduction process of the size of the data file of an image. It is a figure which shows an example of the reduction process of the size of the data file of an image. It is a figure which shows an example of the reduction process of the size of the data file of an image. It is a figure which shows an example of the reduction process of the size of an audio | voice data file. It is a figure which shows an example of the reduction process of the size of an audio | voice data file. It is a figure which shows the other structural example of the information communication system which concerns on this invention. It is a figure which shows an example of the table hold | maintained at a user terminal capability holding | maintenance part.

Explanation of symbols

10 mbox10
DESCRIPTION OF SYMBOLS 11, 12 User area | region 11a, 11b Message 20 Mail server 22 Message analysis part 23 User terminal capability holding part 24 File format conversion part 25 Notification part 30 Mobile communication network 40 Mobile phone terminal device 61 Normal mail processing part 62 SMS processing part

Claims (3)

Terminal capability holding means for holding information indicating the format of a data file that can be used in the information communication terminal device to which the electronic mail service is provided;
Format detection means for detecting the format of the data file attached to the received message (received message);
Referring to the terminal capability holding means, it is determined whether the format of the data file detected by the format detecting means is a format that can be used in the information communication terminal device corresponding to the destination of the received message to which the data file is attached. Determination means to perform,
According to the determination result of the determination means, if the data file is not in a format that can be used in the information communication terminal device, the data file can be used in the information use terminal device for conversion means for converting the data file. A mail server device comprising conversion control means for converting to a different format.   The mail server device according to claim 1, further comprising a reception notification unit that transmits a reception notification including information indicating the data file converted by the conversion unit to the information communication terminal device. Terminal capability holding means for holding information indicating the format of a data file that can be used in the information communication terminal device to which the electronic mail service is provided, and the format of the data file attached to the received message (received message) A format that can be used in the information communication terminal device that corresponds to the destination of the received message to which the data file is attached, with reference to the format detection means and the terminal capability holding means. In accordance with the determination result of the determination means and the determination result of the determination means, if the data file is not in a format that can be used in the information communication terminal device, the conversion means for converting the format of the data file, Conversion control means for converting the data file into a format usable in the information using terminal device; Information communication system comprising: a mail server with.

Images