Patent Publication Number: US-7213078-B2

Title: E-mail service apparatus, system, and method

Description:
FIELD OF THE INVENTION 
   The present invention relates to an e-mail service system, apparatus, and method for providing information to a user using an e-mail system. 
   BACKGROUND OF THE INVENTION 
   Along with the development of communication infrastructures and progress of information communication technologies, an information service using the Internet can be made. In the information service using the Internet, not only text information but also multimedia information containing an image, audio, and the like can be provided. 
   Users who receive information services via the Internet can make communication and exchange of information using e-mail messages among users by registering their mail accounts required to use e-mail. 
   Normally, e-mail information is text. Also, binary files such as application data (document files) and the like created by users can be attached to e-mail information using an encode technique to text data and a decode technique from text data, and can be exchanged among users. 
   On the other hand, along with the development of communication infrastructures, the progress of information communication technologies, and size reductions of terminals required to use them, connection to the Internet can be established not only from desktop personal computers but also portable terminals for a mobile environment such as portable phones and the like. As a result, users who utilize e-mail via portable terminals are increasing rapidly. 
   Means that can acquire information distributed on the Internet are not limited to personal computers, but are wide-ranging devices including portable terminals, e-mail dedicated terminals, and the like. For this reason, unique physical and performance limitations such as limitations on the information size that can be received, limitations on display performance of terminals such as the display size, color, resolution, and the like vary. Even in communications or exchange of e-mail messages between personal computers which suffer less limitations, an information processing environment common to both the sender and receiver is often deficient. 
   In such environment, if the receiver&#39;s environment cannot process received information, that information is discarded without being acquired as information. Hence, information to be exchanged may be lost unless information exchange is made after both the environments are confirmed in advance. 
   For example, portable terminals can exchange e-mail messages via the Internet. However, the number of received characters per mail message, and information contents that can be handled (attachment of computer digital files or binary files) are limited, and information beyond such limitations is discarded. Therefore, information that an e-mail receiver cannot normally receive (which may be discarded before it reaches a terminal) may be generated unless the e-mail receiver informs an e-mail sender of such limitations. 
   One can imagine from the domain name of a mail address that the destination of information is a portable terminal, but such address makes no difference from that of a standard Internet mail address system. Furthermore, some portable terminal users forward mail messages with mail addresses, which are normally used in terminals with different limitations on e-mail reception performance such as desktop personal computers or the like, to mail addresses of portable terminals. Therefore, the senders cannot easily determine the information reception performance of receivers&#39; terminals. As a result, it is very difficult for an e-mail sender to predict a receiver&#39;s environment, and to process information to allow the receiver to receive it upon sending the information. 
   Therefore, many e-mail messages exchanged via portable terminals currently suffer loss of information. 
   In order to avoid such problems, a technique for forwarding an e-mail message to a portable terminal to one account on a server that exploits the World Wide Web technique, and browsing that message via a mechanism of the World Wide Web is already available. However, such technique can only avoid a limitation on the number of received characters at a portable terminal, but cannot cope with browsing of binary files and data acquisition. In this arrangement, since an e-mail message to a portable terminal is unconditionally forwarded to a World Wide Web server, the portable terminal user must always check if mail messages have been forwarded to the World Wide Web server, thus imposing a heavy load on the portable terminal user. 
   When an e-mail sender attaches a document file or the like created using some application to an e-mail message, a user who uses a portable terminal alone as connection means to the Internet can expand the attached file on the portable terminal, but the expanded file often goes beyond the limitations such as display performance or the like of the portable terminal. 
   Furthermore, not only in a portable terminal but also in an Internet connection terminal such as a desktop personal computer or the like, which suffers less limitations as reception means, a mail receiving terminal must have an application which is the same as that used when an e-mail sender created an attached document, or is compatible to that application, so as to expand and display document information attached to an e-mail message. However, such application is not always present in the e-mail receiving terminal. If the receiver does not have any application which is the same as that used when the sender created an attached document or is compatible to that application, he or she cannot review information sent from the e-mail sender. 
   In such environment, the receiver cannot confirm information sent from the sender unless he or she prepares for an environment compatible to the sending environment of the sender with much labor. 
   SUMMARY OF THE INVENTION 
   The present invention has been made in consideration of the above problems, and has as its object to provide the contents of an e-mail message by converting them into a data format corresponding to the performance of an e-mail receiving terminal. It is another object of the present invention to allow sending of a forward message to another receiving terminal. 
   According to the present invention, the foregoing object is attained by providing an information service apparatus comprising: reception means for receiving information to be sent to a user; determination means for determining a destination of the information to be sent received by the reception means on the basis of information set in correspondence with the user; split means for splitting data contained in the information to be sent for respective types of contents; instruction means for instructing format conversion to match each data split by the split means with processing performance of the destination determined by the determination means; and service means for combining the data that have undergone format conversion on the basis of the instruction of the instruction means, and providing the combined data to the destination. 
   According to another aspect of the present invention, the foregoing object is attained by providing an information processing apparatus, comprising: judgment means for judging a conversion unit that can convert data into a predetermined format; and instruction means for instructing the conversion unit judged by the judgment means to convert the data. 
   In still another aspect of the present invention, the foregoing object is attained by providing an information processing apparatus comprising: reception means for receiving data; conversion means for converting the received data into a predetermined format; and sending means for sending the data that has been converted into the predetermined format, wherein the received data is data which is instructed by an external apparatus to undergo conversion into the predetermined format. 
   In still another aspect of the present invention, the foregoing object is attained by providing an information service system comprising: reception means for receiving information to be sent to a user; determination means for determining a destination of the information to be sent received by the reception means on the basis of information set in correspondence with the user; split means for splitting data contained in the information to be sent for respective types of contents; instruction means for instructing format conversion to match each data split by the split means with processing performance of the destination determined by the determination means; conversion means for executing format conversion of the split data instructed by the instruction means; and service means for combining the data that have undergone format conversion on the basis of the instruction of the instruction means, and providing the combined data to the destination. 
   In still another aspect of the present invention, the foregoing object is attained by providing an information processing system comprising: judgment means for judging a conversion module that can convert data into a predetermined format; and instruction means for instructing the conversion module judged by the judgment means to convert the data. 
   In still another aspect of the present invention, the foregoing object is attained by providing an information processing system comprising: reception means for receiving data; conversion means for converting the received data into a predetermined format; and sending means for sending the data that has been converted into the predetermined format, wherein the received data is data which is instructed by judgment means present on a network to undergo conversion into the predetermined format. 
   Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
       FIG. 1  is a schematic block diagram showing the arrangement of a service system according to an embodiment of the present invention; 
       FIG. 2  is a schematic block diagram showing the arrangement of a service system according to an embodiment of the present invention; 
       FIG. 3  is a schematic block diagram showing the arrangement of a mail server; 
       FIG. 4  is a schematic block diagram showing the arrangement of a judgment module; 
       FIG. 5  is a schematic block diagram showing the arrangement of a conversion module; 
       FIG. 6  is a schematic block diagram showing the arrangement of a setup module; 
       FIG. 7  is a schematic block diagram showing the arrangement of a net database; 
       FIG. 8  shows an example of the data configuration of a user information table; 
       FIG. 9  shows an example of the data configuration of a user home information table; 
       FIG. 10  shows an example of the data configuration of a user office information table; 
       FIG. 11  shows an example of the data configuration of a user portable terminal information table; 
       FIG. 12  shows an example of the data configuration of a user conversion setup table; 
       FIG. 13  shows an example of the data configuration of a conversion module table; 
       FIG. 14  shows an example of the data configuration of a service company table; 
       FIG. 15  shows an example of the data configuration of a service site table; 
       FIG. 16  shows an example of the data configuration of a use directory service table; 
       FIG. 17  shows an example of the data configuration of a portable terminal performance table; 
       FIG. 18  is a flow chart showing the sequence for user registration and user conversion setup registration; 
       FIG. 19  shows an example of a cover page in a Web server of a net mail service of this embodiment; 
       FIG. 20  shows an example of a user setup cover page in the Web server of the net mail service of this embodiment; 
       FIG. 21  shows an example of a member registration window in the Web server of the net mail service of this embodiment; 
       FIG. 22  shows an example of a forward destination designation window in the Web server of the net mail service of this embodiment; 
       FIG. 23  shows an example of a forward destination designation window in the Web server of the net mail service of this embodiment; 
       FIG. 24  shows an example of a forward destination designation window in the Web server of the net mail service of this embodiment; 
       FIG. 25  shows an example of a forward destination designation window in the Web server of the net mail service of this embodiment; 
       FIG. 26  shows an example of a user setup change cover page in the Web server of the net mail service of this embodiment; 
       FIG. 27  shows an example of a service select window in the Web server of the net mail service of this embodiment; 
       FIG. 28  shows an example of a received mail list in the Web server of the net mail service of this embodiment; 
       FIG. 29  shows a display example of a received mail message in the Web server of the net mail service of this embodiment; 
       FIG. 30  shows an example of a mail forwarding setup window in the Web server of the net mail service of this embodiment; 
       FIG. 31  shows an example of a mail forwarding setup or new mail creation window in the Web server of the net mail service of this embodiment; 
       FIG. 32  shows an example of a mail forwarding setup window in the Web server of the net mail service of this embodiment; 
       FIG. 33  shows an example of a mail forwarding setup window in the Web server of the net mail service of this embodiment; 
       FIG. 34  shows an example of a new mail creation window in the net mail service Web server of this embodiment; 
       FIG. 35  shows an example of a new mail creation window in the Web server of the net mail service of this embodiment; 
       FIG. 36  shows an example of a registration window of another site associated with a conversion service in the net mail service Web server of this embodiment; 
       FIG. 37  shows an example of a registration window of another site associated with a conversion service in the Web server of the net mail service of this embodiment; 
       FIG. 38  shows an example of a conversion module registration window in the Web server of the net mail service of this embodiment; 
       FIG. 39  shows an example of a directory service site priority registration window in the Web server of the net mail service of this embodiment; 
       FIG. 40  is a flow chart for explaining the process of the judgment module in a net mail service site of this embodiment; 
       FIGS. 41A to 41D  are flow charts for explaining the process for generating data which can be displayed on a Web; 
       FIGS. 42A to 42D  are flow charts for explaining the process for generating a Web page compatible to a portable terminal; 
       FIGS. 43A to 43D  are flow charts for explaining the process for generating data that can be sent to a FAX; 
       FIG. 44  is a flow chart for explaining the process for generating data which can be displayed on a portable terminal; 
       FIGS. 45A to 45D  are flow charts for explaining the process for generating data that can be displayed on a portable terminal; 
       FIG. 46  is a flow chart for explaining the process for selecting one of a plurality of conversion modules; 
       FIG. 47  is a flow chart for explaining a stability update process; 
       FIG. 48  is a flow chart for explaining the process of the judgment module in a directory service site of this embodiment; 
       FIG. 49  is a flow chart for explaining the process of the judgment module in a conversion service site of this embodiment; 
       FIG. 50A  shows an example of an XML file used upon registration of a conversion module of this embodiment; 
       FIG. 50B  shows an example of a mail message sent when items of the conversion module table are not updated; 
       FIG. 51A  shows an example of an XML file used upon registration of a conversion module of this embodiment; 
       FIG. 51B  shows an example of a message sent when no corresponding conversion module is found in a conversion service site or directory service site; 
       FIG. 52  shows an example of an XML file used upon searching for a conversion module of this embodiment; and 
       FIG. 53  shows an example of an XML file used upon searching for a conversion module of this embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will now be described in detail in accordance with the accompanying drawings. 
   This embodiment will explain an information service system. In this system, when information is provided to the user using an e-mail system, if information that cannot be expanded or displayed in an environment of the receiver terminal of an e-mail message is sent, the system notifies the user of its summary and acquisition method, and can provide information which cannot be expanded or displayed due to environmental limitations in a conventional system to a receiver in various forms. 
   &lt;System Arrangement&gt; 
   A service system (to be referred to as a net mail service hereinafter) to be explained in this embodiment has a mail server, a module for judging based on user&#39;s setups if it is possible to display or output to a medium of user&#39;s choice, and generating a document which matches the medium of user&#39;s choice (to be referred to as a judgment module hereinafter), a module for converting a specific format into another specific format (to be referred to as a conversion module hereinafter), a module for setting user information and a medium of user&#39;s choice (to be referred to as a setup module hereinafter), and a storage device for storing user information, user&#39;s setups of inter-media conversion (to be referred to as user conversion setups hereinafter), information of servers that implement inter-media conversion, data sent via mail, and the like (to be referred to as a net database hereinafter). 
     FIG. 1  is a schematic diagram for explaining the arrangement of the service according to this embodiment. As shown in  FIG. 1 , the service according to this embodiment is constituted by four different sites, i.e., site 1 , site 2 , site 3 , and site 4 .  FIG. 1  shows four sites for the sake of easy understanding, but the number of sites is not limited to four. As other site arrangements, for example, the following configurations are available: 
   (1) a configuration formed of one or a plurality of site 1 ; 
   (2) a configuration formed of one or a plurality of site 1  and one or a plurality of site 2 ; 
   (3) a configuration formed of one or a plurality of site 1 , one or a plurality of site 3 , and one or a plurality of site 4 ; 
   (4) a configuration formed of one or a plurality of site 1 , one or a plurality of site 2 , one or a plurality of site 3 , and one or a plurality of site 4 ; and 
   (5) a configuration in which site 1  does not have any conversion module in each of configurations (2) to (4). 
   In  FIG. 1 , site 1 , site 2 , site 3 , and site 4  assume minimum required arrangements which provide functions to be described later. Such assumption is also made for the sake of easy understanding in the following detailed description of site 1 , site 2 , site 3 , and site 4 , but does not deny the presence of a single site including site 1  and site 3  (and other combinations), and a site having both functions of site 1  and site 3  (and combinations of other functions). In the following description, site 1  will be referred to as a net mail service site, site 2  and site 4  will be referred to as conversion service sites, and site 3  will be referred to as a directory service site. 
   Note that site 2  and site 4  are conversion service sites having similar functions. Although site 2  and site 4  are conversion service sites having similar functions,  FIG. 1  illustrates direct communication relationships only between site 1  and site 3 , and between site 3  and site 4 . Such assumption is also made for the sake of easy understanding, and direct communication relationships may be established between site 2  and site 3 , and between site 1  and site 4 . 
     FIG. 2  also illustrates communication methods of site 1 , site 2 , site 3 , and site 4  of this embodiment, which are not shown in  FIG. 1 . In this embodiment, as shown in  FIG. 2 , communications using CGI on Web servers  600 ,  600   a ,  600   b , and  600   c  are made using HTTP, and communications are made via mail servers using SMTP among judgment modules  200 ,  200   a ,  200   b , and  200   c . However, the present invention is not limited to such specific protocols, and dedicated protocols or versatile protocols other than HTTP and SMTP may be used. That is, communications using dedicated protocols or versatile protocols other than HTTP and SMTP can be made, and if inter-site communication means are present independently, Web servers and mail servers in site 2 , site 3 , and site 4  are not indispensable. The following explanation will be given using  FIG. 2 , and the same applies to  FIG. 1  except for paragraphs that explain communication methods among judgment modules. 
   Referring to  FIG. 2 , reference numeral  100  ( 100   a ,  100   b ,  100   c ) denotes a mail server;  200  ( 200   a ,  200   b ,  200   c ), a judgment module;  300  ( 300   a ,  300   c ), a conversion module;  500  ( 500   a ,  500   b ,  500   c ), a setup module; and  400  ( 400   a ,  400   b ,  400   c ), a net database. In  FIG. 2 , only one conversion module  300  ( 300   a ,  300   c ) is illustrated in each site, but a plurality of conversion modules may be present in each site, as will be described later. As described above, since site 1 , site 3 , site 3 , and site 4  assume minimum required functions, some functions of the judgment modules  200 ,  200   a ,  200   b , and  200   c  are different. 
   In the above arrangement, a mail message received by the mail server  100  is split by the judgment module  200  in correspondence with formats, and each data is passed to and converted by the appropriate conversion module  300 , the conversion module  300   a  of site 2 , or the conversion module  300   c  of site 4  selected at site 3  in accordance with user conversion setups. The judgment module  200  of site 1  receives converted data and generates a document that matches each output destination medium using the converted data, and the generated document is sent to each medium such as a user&#39;s Web browser, portable terminal, or facsimile device via a Web server  600 , the mail server  100 , or a FAX server  650  and is displayed or output. The contents of the user conversion setups used in the judgment process in the judgment module  200  are generated and changed by the setup module  500 . Individual modules will be described in detail below. 
   In this embodiment, in order to provide flexible services to the user, the setup module  500  allows user&#39;s setups. However, if uniform services are to be provided to all users, identical conversion setups need only be used, and the setup module can be omitted in such case. That is, the setup module is an option, and is not indispensable. 
   The mail server  100  is a module for exchanging mail messages, and may or may not run on a server on which the judgment module  200  is running. Also, a mail reception function maybe either a function of directly receiving SMTP mail messages, or a function of periodically accessing an independent mail server using an arbitrary protocol such as POP3 or the like to acquire mail messages. That is, upon application to this embodiment, the mail server is required to have means for passing received data to another program module, and to issue a mail message to a medium (another mail server, a portable medium having a mail function, or the like) that expresses the conversion result. 
   The judgment module  200  splits a mail message received by the mail server  100  or a mail message stored in the net database  400  into data for respective formats contained in that mail message. In order to convert each individual part obtained by splitting into a format which matches a medium of user&#39;s choice, an appropriate conversion module is selected. If the conversion module  300  in site 1  is an appropriate one, a conversion instruction is issued to the conversion module  300 . If it is determined based on information in the net database in site 1  that the conversion module  300   a  in site 2  is appropriate, a conversion instruction is issued from the judgment module  200  to the conversion module  300   a  via the judgment module  200   a.    
   Furthermore, if an appropriate conversion module and its site cannot be determined, an appropriate conversion module is judged using the judgment module  200   b  of the directory service site (site 3 ). If a conversion module in a conversion service site selected as a result of checking in that directory service site is the conversion module  300   c  in site 4 , conversion is made by the conversion module  300   c.    
   Note that an appropriate format after conversion is determined by looking up a user conversion setup table (to be described later) stored in the net database  400  of a conversion request source site (site 1 ). A document for a medium of user&#39;s choice is generated using data returned from the conversion module  300 ,  300   a , or  300   c.    
   The judgment module  200   b  in site 3  selects a conversion module appropriate for the conversion instruction from the judgment module  200  from a conversion module table in the net database  400   b  (to be described later), and sends a conversion instruction to an appropriate judgment module (e.g., judgment module  200   c  in site 4 ) in the conversion service site where the appropriate conversion module is present. If no appropriate conversion module is present in the conversion module table, a message indicating that no appropriate conversion is available is sent to the judgment module  200 . 
   The judgment module  200   a  in site 2  selects the conversion module  300   a  appropriate for the conversion instruction from the judgment module  200 , and returns the conversion result to the judgment module  200 . Likewise, the judgment module  200   c  in site 4  selects the conversion module  300   c  appropriate for the conversion instruction from the judgment module  200 , and returns the conversion result to the judgment module  200 . 
   The conversion modules  300 ,  300   a ,  300   b  are filters each for converting a specific format into another specific format. As the simplest example, a module for converting a TIFF format as an image format into a JPEG format as another image format may be used. Since such module converts between specific formats, there are a plurality of conversion modules in correspondence with format conversions that the judgment module  200  can process. Note that  FIG. 1  illustrates the conversion modules  300 ,  300   a , and  300   c , but two or more conversion modules can be present in a single site. 
   The setup module  500  is a mechanism for accepting user registration, user conversion setups, setups associated with conversion modules, and the like, and storing these setup contents in the net database  400 . Likewise, the setup modules  500   a ,  500   b , and  500   c  are mechanisms for accepting setups associated with conversion modules and the like, and storing them in the net databases  400   a ,  400   b , and  400   c , respectively. In this embodiment, the setup modules are launched from the Web servers  600 ,  600   a ,  600   b , and  600   c  via CGI or the mail servers  100 ,  100   a ,  100   b , and  100   c  via mail messages, but this does not mean that setups using a dedicated terminal, phone or the like are not available. That is, setups and their changes can be made using a dedicated terminal, voice guidance via phone, or the like. 
   The net databases  400 ,  400   a ,  400   b , and  400   c  store user registration contents, user conversion setups, accounting information, information of other sites associated with conversion, mail data, and the like. 
   The Web server  600  and FAX server  650  are respectively connected to media (a computer having a Web browser, a portable terminal having a Web browser, a facsimile device, and the like) to which a document generated using converted data is output. In this embodiment, the Web server  600  is used to access the setup module  500 . In this case, the Web server  600  and setup module  500  may be physically present in a single server or different servers. 
   Data to be forwarded to a facsimile device that outputs a document is sent via the FAX server  650 . Alternatively, a document may be sent by directly calling the facsimile device. 
   In order to immediately inform the user that a mail message has arrived and undergone data conversion, a mail conversion result indicating that information has been uploaded onto the Web server  600 , that FAX data has been sent and its destination, or the like can be sent to the portable terminal via the mail server  100 . 
   In this embodiment, the mail server  100 , Web server  600 , and FAX server  650  are selected as information service means to media that express the conversion result, but implementation of other media is not limited. For example, if a conversion module for converting text into audio data is available, a voice telephone may be selected as a medium that expresses the conversion result. Also, a user&#39;s portable terminal or facsimile device need not be a dedicated one. 
   As examples of services realized by the aforementioned system, this embodiment will mainly explain the following services. 
   (1) User registration: This service registers the ID and password used in user authentication, information required for accounting, personal information, and the like. 
   (2) Registration/change of user conversion setups: This service registers or changes the setups of a forwarding destination and conversion used upon providing an automatic mail conversion service. 
   (3) Data display on Web: This service displays converted mail information on a Web. 
   (4) Data display on Web compatible to portable terminal: This service displays mail information converted for a Web browser on a portable terminal. 
   (5) Data display on portable terminal: This service displays converted mail information on a portable terminal. 
   (6) Data display via FAX: This service outputs converted mail information using FAX. 
   (7) Registration of other sites associated with conversion service: This service registers information of other sites used in the conversion service. 
   (8) Site registration content verification service: This service verifies if information of other sites registered in the net database is correct. 
   (9) Automatic mail conversion service: This service automatically converts the contents of a mail message into a format suitable for another medium in accordance with setups. 
   (10) Interactive mail conversion service: This service converts the contents of a mail message into a format suitable for another medium interactively with the user. 
   The aforementioned services will be described in detail later. Note that the services and functions in this embodiment are not limited to such specific ones. 
   &lt;Arrangement of Mail Server&gt; 
     FIG. 3  is a schematic block diagram showing the arrangement of the mail server  100  ( 100   a ,  100   b ,  100   c ). Reference numeral  101  denotes a controller which comprises a CPU  102  and memory  103 . The CPU  102  implements mail send/receive control, and creation and erasure of mail accounts by executing a mail send/receive program  103   a  and mail account create/erase program  103   b  stored in the memory  103 . Reference numeral  104  denotes a communication unit, which is used to exchange mail data via a line, to store a received mail message in the net database  400 , and to read out data from the net database  400  upon sending a mail message. 
   &lt;Arrangement of Judgment Module&gt; 
     FIG. 4  is a schematic block diagram showing the arrangement of the judgment module  200  ( 200   a ,  200   b ,  200   c ) Reference numeral  201  denotes a controller which comprises a CPU  202  and memory  203 . The CPU  202  implements a judgment process associated with data conversion by executing a mail split program  203   a , conversion module select program  203   b , and mail re-generate program  203   c  stored in the memory  203 . Reference numeral  204  denotes a communication unit which is used to exchange data with other modules and other sites, and to access the net database  400  ( 400   a ,  400   b ,  400   c ) when received mail messages stored in the net database  400  are read out, when processed data are added to the net database  400  ( 400   a ,  400   b ,  400   c ), when the contents of user conversion setups, information associated with conversion modules, and the like are stored in the net database  400  ( 400   a ,  400   b ,  400   c ), and so forth. In this embodiment, the judgment module  200  ( 200   a ,  200   b ,  200   c ) executes an access mediation process between other modules and other servers, and the net database  400  ( 400   a ,  400   b ,  400   c ). However, such access may be made without the intervention of the judgment module  200  ( 200   a ,  200   b ,  200   c ). 
   &lt;Arrangement of Conversion Module&gt; 
     FIG. 5  is a schematic block diagram showing the arrangement of the conversion module  300  ( 300   a ,  300   c ). Reference numeral  301  denotes a controller, which comprises a CPU  302  and memory  303 . The CPU  302  converts the format of provided data by executing a format conversion program  303   a  stored in the memory  303 . Reference numeral  304  denotes a communication unit, which is used to exchange data with other modules, and to access data on the net database  400  ( 400   a ,  400   b ,  400   c ) when data before conversion is acquired from the net database  400  ( 400   a ,  400   b ,  400   c ) and when data after conversion is stored in the net database  400  ( 400   a ,  400   b ,  400   c ). 
   &lt;Arrangement of Setup Module&gt; 
     FIG. 6  is a schematic block diagram showing the arrangement of the setup module  500  ( 500   a ,  500   b ,  500   c ). Reference numeral  501  denotes a controller, which comprises a CPU  502  and memory  503 . The CPU  502  implements setting and change processes of user conversion setups by executing a user conversion setup program  503   a  and XML parser program  503   b  stored in the memory  503 . Reference numeral  504  denotes a communication unit which is used to receive designations of setup contents by interacting with the user via a line, to communicate with other modules, and to access data on the net database  400  ( 400   a ,  400   b ,  400   c ) upon storing the contents of user conversion setups, information associated with conversion modules, and the like in the net database  400  ( 400   a ,  400   b ,  400   c ). 
   &lt;Arrangement of Net Database&gt; 
     FIG. 7  is a schematic block diagram showing the arrangement of the net database  400  ( 400   a ,  400   b ,  400   c ). Reference numeral  401  denotes a controller, which comprises a CPU  402  and memory  403 . The CPU  402  manages data stored in a storage medium  405  by executing a database management system  403   a  stored in the memory  403 . Reference numeral  404  denotes a communication unit, which is used to exchange data with other modules via a line. The storage medium  405  stores and saves data to be managed by the database management system  403   a . The data to be stored include a table group  406  such as user information and the like, a data entity  407  of mail data and the like, and so forth. 
   The table group  406  includes a user information table  406   a  ( FIG. 8 ), user home information table  406   b  ( FIG. 9 ), user office information table  406   c  ( FIG. 10 ), user portable terminal information table  406   d  ( FIG. 11 ) , user conversion setup table  406   e  ( FIG. 12 ), conversion module table  406   f  ( FIG. 13 ), service company table  406   g  ( FIG. 14 ), service site table  406   h  ( FIG. 15 ), use directory service table  406   i  ( FIG. 16 ), and portable terminal performance table  406   j  ( FIG. 17 ). The respective tables will be described below. In this embodiment, since the functions of sites are limited, unnecessary tables may be present in site 1 , site 2 , site 3 , and site 4 . The net mail service site (site 1 ) has all tables, i.e., the user information table  406   a , user home information table  406   b , user office information table  406   c , user portable terminal information table  406   d , user conversion setup table  406   e , conversion module table  406   f , service company table  406   g , service site table  406   h , use directory service table  406   i , and portable terminal performance table  406   j . On the other hand, the conversion service site (site 2 , site 4 ) or the directory service site (site 3 ) has the conversion module table  406   f , service company table  406   g , and service site table  406   h.    
     FIG. 8  shows an example of the data configuration of the user information table. The user information table  406   a  is generated and recorded when the user makes user registration, and stores the user ID and password used in user authentication, and credit card information, accounting record, and the like used in user accounting. 
   Note that the user ID is also used as a mail account generated in the mail server in the net mail service of this embodiment. For example, if the user ID is aaa and the domain of the net mail service site is hoge.ne.jp, a mail address assigned to the user in the mail server is aaa@hoge.ne.jp. 
     FIG. 9  shows an example of the data configuration of the user home information table. The user home information table  406   b  is generated and recorded when the user makes user registration or when he or she uses net mail services. The user home information table  406   b  stores the user&#39;s home telephone number and address, and the IDs of display/output media (e.g., home FAX number, home mail address) used in the home. Note that the user ID is the same as that registered in the user information table shown in  FIG. 8 . 
     FIG. 10  shows an example of the data configuration of the user office information table. The user office information table  406   c  is generated and recorded when the user makes user registration or when he or she uses net mail services. The user office information table  406   c  stores the address of an office of the user (office telephone number, office address, and the like), and the IDs of display/output media (e.g., office FAX number, office mail address) used in that office. Note that the user ID is the same as that registered in the user information table shown in  FIG. 8 . 
     FIG. 11  shows an example of the data configuration of the user portable terminal information table. The user portable terminal information table is generated and recorded when the user makes user registration or when he or she uses net mail services, and stores information associated with a user&#39;s portable terminal, as shown in  FIG. 11 . Note that the user ID is the same as that registered in the user information table shown in  FIG. 8 . 
     FIG. 12  shows an example of the data configuration of the user conversion setup table. In this embodiment, setups as to whether to make display or output on respective media via the mail server  100 , Web server  600 , and FAX server  650  are made using the user conversion setup table  406   e . The user conversion setup table  406   e  is used to make setup so that appropriate information can be delivered to an appropriate device when the user uses an automatic conversion service. Note that the user ID is the same as that registered in the user information table shown in  FIG. 8 . 
   The user can select display (output) on respective media via the mail server  100 , Web server  600 , and FAX server  650  using the setup module  500 , and can also select the display (output) forms of an attached document for respective output destinations. When the contents are displayed or output via the Web server  600  or FAX server  650 , a message indicating that such display/output process is done can be sent to the portable terminal via the mail server  100 . 
   For example, assume that a mail message attached with an image file is received while selecting display on a Web. Normally, the image formats that a Web browser supports are limited to JPEG, GIF, and the like. In such case, in order to review an attached image with another format, the user must prepare image display software compatible to that format. However, if the user selects (function of converting image format other than JPEG and GIF to JPEG upon displaying attached image on Web=ON) in the user conversion setup table  406   e , the format of the image file is automatically converted into JPEG, and that image can be displayed on a Web browser. Then, a part such as mail body text or the like, which can be browsed even on a portable terminal, and a message indicating that the image is uploaded to the Web server  600 , are sent to the portable terminal via the mail server  100 . The above sequence is similarly done for a wordprocessor document. Note that conversion of image formats and wordprocessor documents is supported only when conversion modules which are used to convert such image formats and wordprocessor documents are available, and not all formats are converted. However, if a format is open to the public, a conversion service of that format can be provided by implementing a conversion module corresponding to that format. 
   In case of a format which is not open to the public, a conversion module used to convert that format is available only when a given fee is paid. Hence, whether or not use of a pay conversion module is permitted can be selected (such setup can be made by selecting [use pay conversion in Web display], [use pay conversion in display on portable terminal], and [use pay conversion in display on FAX] in the user conversion setup table  406   e ). If a plurality of conversion modules with an identical function are present, a criterion (price, compatibility level, stability) used upon selecting a conversion module in such case can be set. Since these setups are allowed, the user can avoid wasteful expense, and can use a conversion module with stable quality. 
   Note that the user need not always select only one of the mail server  100 , Web server  600 , and FAX server  650  as a display/output destination, and the contents of one mail message can be displayed or output to a plurality of or all media. The display or output contents on these plurality of media need not always be identical. For example, mail body text and the summary of an attached wordprocessor document can be sent to a portable terminal, and full wordprocessor document text can be output using FAX via the FAX server  650 . 
   The functions of the user conversion setup table have been explained. Since mail data is saved in the data entity  407 , conversion can also be made interactively with the user, as will be described later. In this case as well, the user conversion setup table  406   e  is used. When setups for interactive conversion are stored in the user conversion setup table  406   e , a [temporary flag] is set “True” (“False” in case of automatic conversion). For example, when a wordprocessor document can only be browsed using a pay conversion module, a message indicating only arrival of a wordprocessor document is sent to a portable terminal via the mail server  100 . Upon receiving this message, the user accesses the Web server  600  to select that mail message, and designates a conversion method of the mail message. The designation result is stored in the user conversion setup table  406   e , and the [temporary flag] in the table is set “True” accordingly. The judgment module  200  sends a part to be converted of the mail message to an appropriate conversion module  300  by looking up the user conversion setup table  406   e , receives the conversion result from the conversion module, and generates a document compatible to the output destination, thus allowing the user to browse the mail contents. 
     FIG. 13  shows an example of the data configuration of the conversion module table. The conversion module table  406   f  is used to describe characteristics of conversion modules ( 300 ,  300   a ,  300   c ). The judgment modules  200 ,  200   a ,  200   b , and  200   c  can select conversion modules with appropriate input and output formats by looking up this conversion module table  406   f . Normally, the input and output formats are determined based on MIME and extension. However, some output formats like “summary of wordprocessor document” in  FIG. 12  cannot be determined using only MIME and extension, and “output format (unique)” is added to determine such formats. 
   As has been described in  FIG. 12 , since pay conversion modules are present, an item ([price]) indicating a conversion price required per page is prepared. In this embodiment, the conversion price is calculated per page, but the price may be determined using other criterion such as the data size and the like. 
   Furthermore, since items that store the use count and success count ([use count], [success count]) are prepared to recognize the stability of each conversion module, the stability of conversion can be recognized by dividing the success count by the use count. In case of an application file or the like, since it is often impossible to convert all functions, an item ([compatibility level]) is prepared to indicate a limit of reproducibility. Items [compatibility level], [price], [use count], and [success count] are used as criteria when the judgment module selects a conversion module. 
     FIG. 14  shows an example of the data configuration of the service company table. The service company table  406   g  is used to describe basic information of a company that manages one or a plurality of the conversion service site, net mail service site, and directory service site. Since use of the conversion service site or directory service site may often require accounting, an item [scheduled payment record] is prepared to describe a payment payable to a company that manages the conversion service site or directory service site, or a charge against a company that manages the conversion service site or directory service site. Every time the conversion service site or directory service site is used, [price] in the conversion module table  407   f  or an amount reported from the directory service site (to be described later) is added to or subtracted from the scheduled payment record. Note that addition is made when a service incurs a payment payable to a company that manages the conversion service site or directory service site, and subtraction is made when a service incurs a charge against a company that manages the conversion service site or directory service site. 
     FIG. 15  shows an example of the data configuration of the service site table. The service site table  406   h  is used to describe basic information of one of the conversion service site, net mail service site, and directory service site. Since use of the conversion service site or directory service site may often require accounting, an item [site-dependent scheduled payment record] is prepared to describe a payment payable to a company that manages the conversion service site or directory service site, or a charge against a company that manages the conversion service site or directory service site. Every time the conversion service site or directory service site is used, [price] in the conversion module table  407   f  or an amount reported from the directory service site (to be described later) is added to or subtracted from the [site-dependent scheduled payment record]. Note that addition is made when a service incurs a payment payable to a company that manages the conversion service site or directory service site, and subtraction is made when a service incurs a charge against a company that manages the conversion service site or directory service site. 
     FIG. 16  shows an example of the data configuration of the use directory service table. The use directory service table  406   i  is used to describe a directory service site to be used and priority. When the judgment module of a given site fails to determine a conversion module that can implement desired conversion using the conversion module table  406   f , a conversion module is searched for using the directory service, which is designated by looking up this use directory service table  406   i . [Priority] designates the order in which directory service sites are used. The directory service site with priority=1 is searched for a desired conversion module. If the conversion module is found, that module is used. If no desired conversion module is found in the directory service site with priority=1, the directory service site with priority=2 is searched. In this way, the directory service sites are searched in the registered priority order. 
   As described above, since this embodiment assumes minimum required functions of site 1 , site 2 , site 3 , and site 4 , the use directory service table  406   i  can be stored in only the net mail service site (site 1 ). 
     FIG. 17  shows an example of the data configuration of the portable terminal performance table. The portable terminal performance table  406   j  is used to describe the characteristics of a portable terminal. Since the image size that can be displayed largely differs depending on portable terminals, if an image is required to be displayed on the portable terminal, the portable terminal type, portable terminal carrier name, and portable terminal model number registered in the user portable terminal information table  406   d  are acquired, and the image display performance of the portable terminal specified by these kinds of information can be checked by looking up the portable terminal performance table  406   j . In this way, an image can be generated in correspondence with the portable terminal. Likewise, since the maximum number of displayable characters largely differs depending on portable terminals, if a mail message is to be sent to a portable terminal, the maximum number of displayable characters of the portable terminal specified by the portable terminal type, portable terminal carrier name, and portable terminal model number is checked, thus allowing generation of a mail message in correspondence with the portable terminal as a mail destination. 
   In the above description, respective modules in the site are present on physically different machines, but a plurality of modules may be present on a single machine. That is, the mail server  100 , judgment module  200 , conversion module  300 , setup module  500 , and net database  400  in case of site 1 , the mail server  100   a , judgment module  200   a , conversion module  300   a , setup module  500   a , and net database  400   a  in case of site 2 , the mail server  100   b , judgment module  200   b , setup module  500   b , and net database  400   b  in case of site 3 , and the mail server  100   c , judgment module  200   c , conversion module  300   c , setup module  500   c , and net database  400   c  in case of site 4  may be respectively present on identical machines. That is, a common CPU may be used as the CPUs  102 ,  202 ,  302 ,  402 , and  502 . In this case, the mail server  100  ( 100   a ,  100   b ,  100   c ), judgment module  200  ( 200   a ,  200   b ,  200   c ), conversion module  300  ( 300   a ,  300   c ), and setup module  500  ( 500   a ,  500   b ,  500   c ) directly access the storage medium  405  without the intervention of the communication units  104 ,  204 ,  304 ,  404 , and  504 . 
   &lt;Outline of System Operation&gt; 
   In order to receive a net mail service, user registration is required in advance. Also, in order to use an automatic conversion service, user conversion setups must be registered. As described above, in this embodiment, user registration, and registration of user conversion setups are made via the Web server  600 .  FIG. 18  shows the sequence of user registration, and registration of user conversion setups. 
   It is checked in step S 101  if user registration is to be made. If user registration is not complete yet, the flow advances from step S 101  to S 102  to proceed with user registration. In step S 102 , user&#39;s basic information, and information required for accounting of the user are registered. Whether or not a desired user ID can be used is checked and a credit card is authenticated in steps S 103  and S 104 . If no problems are found, the control prompts the user to enter additional information that pertains to a portable terminal, FAX, telephone, and the like used to convert and forward a mail message, and to select service contents (step S 105 ). 
   If it is determined in step S 103  that the desired user ID has already been used by another user, and cannot be used, or if the credit card cannot be authenticated in step S 104 , the flow returns to step S 102  to prompt the user to correct basic information. 
   On the other hand, if user registration is already complete, since user registration is not required, the flow advances from step S 101  to step S 106  to prompt the user to input the user ID and password. If the user is authenticated by the input ID and password (step S 107 ), the control prompts the user (step S 108 ) to select if he or she wants to change user conversion setups (step S 105 ) or to display mail messages on a Web (step S 109 ). If the user wants to change user conversion setups, the control prompts the user to enter additional information that pertains to a portable terminal, FAX, telephone, and the like used to convert and forward a mail message, and to select service contents (step S 105 ). If the user selects to display mail messages on a Web, mail messages which are converted to the Web format in accordance with the registered setups are displayed (step S 109 ). 
   &lt;User Registration&gt; 
     FIG. 19  shows a login window in the Web server of the net mail service of this embodiment. The user who has already acquired his or her user ID enters that user ID in a user ID input field (or area)  700  and a password in a password input field  701 , and then clicks a login button  702 . Then, a window shown in  FIG. 20  is displayed via user authentication (S 101 , S 106 , S 107 ). When the user has clicked a “change setup” button  711  on this window, a window used to register/change user conversion setups (to be described later) is displayed (S 108 , S 105 ). On the other hand, when the user has clicked a “display mail contents” button  710 , a data display window on a Web (to be described later) is displayed (S 108 , S 109 ). 
   On the other hand, when the user has clicked a user registration button  703  in  FIG. 19 , a window in  FIG. 21 , i.e., a window used to make user registration is displayed (S 101 , S 102 ). The user fills all items of input fields  720  to  732 , and presses (clicks) an OK button  733 . If the ID that the user wants to use can be used, and the credit card authentication is successful, a window shown in  FIG. 22  is displayed to allow the user to make user conversion setups (S 103 , S 104 , S 105 ). Note that data are stored in the user information table  406   a  and user home information table  406   b  on the basis of the information input on the window in  FIG. 21 . 
   When the user has clicked a “forward FAX/mail to home” button  740  on the window in  FIG. 22 , an input window shown in  FIG. 23  is displayed. The window in  FIG. 23  is used to enter information of media in the home, and the user enters a FAX number and mail address in input fields  750  and  751  as needed. Based on this information, the user home information table  406   b  is formed. 
   When the user has clicked a “forward FAX/mail to office” button  741  in  FIG. 22 , an input window in  FIG. 24  is displayed. The window in  FIG. 24  is used to enter information of media in the office, and the user enters office information in input fields  760  to  766  as needed. Based on information input on this input window in  FIG. 24 , the user office information table  406   c  is generated. 
   When the user has clicked a “forward FAX/mail to portable terminal” button  742  in  FIG. 22 , a window in  FIG. 25  is displayed. The window in  FIG. 25  is used to enter information of a portable terminal, and the user selects or enters information of the portable terminal in input fields  770  to  775  as needed. For example, the user can select the type of portable terminal such as a portable phone, pager, or the like from a pull-down menu in the area  770 , and can also select a carrier name from a pull-down menu in the area  771 . The user enters the model number of the portable terminal in the field  772 . The user enters a mail address assigned to the portable terminal in the field  775  if it is available. Based on such information, the user portable terminal information table  406   d  is generated. 
   Note that the user must fill all items in  FIG. 21  to identify a person, but he or she can enter information of items in  FIGS. 23 ,  24 , and  25  as needed, since such information is required to provide a service. 
   &lt;Registration/Change of User Conversion Setups&gt; 
   When the user has clicked the “change setup” button  711  in  FIG. 20 , a window in  FIG. 26  which is used to register/change user conversion setups is displayed (S 108 , S 105 ). When the user has clicked a “change use medium” button  790  on this window, the aforementioned window in  FIG. 22  is displayed. Since the actions made upon clicking the buttons  740  to  742  in  FIG. 22  have already been explained, a description thereof will be omitted. 
   On the other hand, when the user has clicked a “change use service” button  791  in  FIG. 26 , a window in  FIG. 27  is displayed. The window in  FIG. 27  is used by the user to set desired services, and the user can set items  800  to  822  as needed. Based on the contents set using the window in  FIG. 27 , the user conversion setup table  406   e  is formed. 
   Check boxes  803 ,  808 ,  814 , and  820  are items used to set whether or not the user permits use of a pay conversion module in automatic conversion. Check boxes  804 ,  809 , and  821  are items used to set whether or not a mail message is sent when a Web page is uploaded to the Web server  600  or a FAX document is sent via the FAX server  650 . 
   A pull-down menu  818  is used to designate a FAX forward destination when use of a forwarding service to FAX is selected by checking one of check boxes  815 ,  816 , and  817 , and the user can select one of the designated FAX numbers of the home, office, and portable terminal. Forwarding to FAX is a pay service since that incurs a telephone charge. Hence, the user can designate a maximum output page count in an input field  819  to avoid a large amount of charge to be incurred due to output of a large quantity of FAX. 
   Radio buttons  822  are used to give a criterion upon selecting a conversion module if more than two conversion modules with identical conversion functions are available. When the user selects one of these three buttons, he or she can set to preferentially select a conversion module with low price, high compatibility level, or high stability when a plurality of conversion modules are available in a single site or directory service site. 
   &lt;Data Display on Web&gt; 
   When the user has clicked the “display mail contents” button  710  in  FIG. 20 , a window shown in  FIG. 28  is displayed (S 108 , S 109 ). That is, a list of mail messages which have been converted to a Web format according to user&#39;s setups is displayed. When the user selects one of mail messages  830 , “From” and “Subject” contents of which are displayed, the data entity  407  (mail body text and attached file) stored in the net database  400  is displayed, as shown in  FIG. 29 .  FIG. 29  shows an example of the contents of a mail message which has been converted into a format that a Web browser can display, and to which an image file is attached. When the check box  801  in  FIG. 27  is checked, and when a mail message has an attached image and a conversion module for converting the format of the attached image to JPEG is available, an image is displayed in addition to body text, as shown in  FIG. 29 . On the other hand, when a wordprocessor document file is attached to a mail message, and the check box  802  in  FIG. 27  is checked, the contents of the wordprocessor document are displayed after body text. 
   In this way, the automatic conversion result is displayed on the Web. Also, interactive data conversion and operations via the Web server can be made. When the user has pressed a delete button  841  in  FIG. 29 , the mail contents displayed on the window in  FIG. 29  are deleted from the net database  400 , and information other than the mail message displayed on the window in  FIG. 29  so far is displayed in the same format as in  FIG. 28 . In this embodiment, the delete button  841  is set only in the window in  FIG. 29 , but may be set in the window in  FIG. 28 . 
   When the user has pressed a forward button  840  in  FIG. 29 , a window in  FIG. 30  is displayed. In order to designate the forwarding destination and method in  FIG. 30 , items  850  to  881  are used to make setups associated with display or output on respective media via the mail server  100 , Web server  600 , and FAX server  650 . 
   When the user wants to forward a mail message without converting it, he or she checks a check box  850  and inputs arbitrary mail addresses in text input fields  851  to  853 . If the user must input a plurality of addresses in one field, he or she can input them by delimiting them by commas. 
   When the user wants to display a mail message on a Web browser via the Web server, he or she can check a check box  854 . If the check box  854  is checked, a Web page is prepared on the Web server  600 , and the URL of this Web page is sent to a mail address entered in a field  855 . For example, assume that an attached document of a mail message is an image with a TIFF format, and the receiver does not have any image display software compatible to the TIFF format. In such case, when the user checks the check box  854  and also a check box  856 , an image can be displayed on a Web browser, thus improving the accuracy of transmission. In this manner, since format conversion using a conversion module is often required upon display on the Web, whether or not an image format or wordprocessor format is converted to display an image or document can be set. Also, whether or not a pay conversion module can be used in that conversion can be set using a check box  858 . 
   When the user wants to display a mail message on a Web page compatible to a portable terminal, he or she can check a check box  859 . When the user checks the check box  859  and inputs information of respective items  860  to  862 , the performance of a portable terminal specified by the items  860  to  862  is checked by looking up the portable terminal performance table  406   j , and a Web page that the portable terminal can display is prepared on the Web server  600 . The URL of this Web page is sent to a mail address entered in a field  863 . If the user does not know the type, carrier name, and model number of a portable terminal as a destination, this conversion function is not available. In this manner, since format conversion using a conversion module is often required upon display on the Web, whether or not an image format or wordprocessor format is converted to display an image or document can be set. At this time as well, the portable terminal performance table  406   j  is looked up to select an image format that matches a portable terminal which displays information. Also, whether or not a pay conversion module can be used in that conversion can be set using a check box  866 . 
   Likewise, when the user wants to forward a mail message to a portable terminal, he or she checks a check box  867  and inputs information of items  868  to  871 , thus generating a mail message optimal to a portable terminal as a destination. If the user does not know about a portable terminal as a destination, he or she can enter only a mail address. However, when the mail address alone is designated, an optimal mail message is not always generated. In case of a portable terminal as well, since format conversion using a conversion module is often required, whether or not an image format or wordprocessor format is converted to send an image or document via mail can be set. Also, whether or not a pay conversion module can be used in that conversion can be set using a check box  875 . 
   When the user wants to forward a mail message to FAX, he or she checks a check box  876  and inputs a destination FAX number in a field  877 , thus forwarding the mail message. If the user must input a plurality of FAX numbers in one field, he or she can input them by delimiting them by commas. In case of FAX transmission, since format conversion using a conversion module is often required, whether or not an image format or wordprocessor format is converted to send an image or document to FAX can be set. Also, whether or not a pay conversion module can be used in that conversion can be set using a check box  881 . Forwarding to FAX is a pay service since it incurs a telephone charge. Hence, the user can designate a maximum output page count in an input field  880  to avoid a large amount of charge to be incurred due to output of a large quantity of FAX. 
   Note that the user need not always select only one of the mail server  100 , Web server  600 , and FAX server  650  as a display/output destination, and the contents of one mail message can be displayed or output to a plurality of or all media. The display or output contents on these plurality of media need not always be identical. For example, mail body text and the summary of an attached wordprocessor document can be sent to a portable terminal, and full wordprocessor document text can be output using FAX via the FAX server  650 . 
   When the user has pressed an OK button  882  in  FIG. 30 , a window in  FIG. 31  is displayed. On the window in  FIG. 31 , the user designates a sending source to be used. From a pull-down menu  885 , the user can select one of four addresses, i.e., (1) the home mail address which is input in  FIG. 23  and is stored in the user home information table  406   b , (2) the office mail address which is input in  FIG. 24 , and is stored in the user office information table  406   c , (3) the mail address of the portable terminal, which is input in  FIG. 25  and is stored in the user portable terminal information table  406   d , and (4) the address of a mail account on the mail server  100  provided by the net mail service. 
   Likewise, from a pull-down menu  886 , the user can select one of three FAX numbers, i.e., (1) the home address and FAX number, which are input in  FIGS. 21 and 23  and are stored in the user home information table  406   b , (2) the office address and FAX number, which are input in  FIG. 24 , and are stored in the user office information table  406   c , and (3) the FAX number of the portable terminal, which is input in  FIG. 25  and is stored in the user portable terminal information table  406   d . The mail address selected on this window is used as the contents of “From” in the headers of a mail message that informs the URL, and a mail message to the portable terminal. Also, the FAX sender name selected on this window is described in the sender column of a front page created upon FAX transmission. 
   When the user has pressed an OK button  887  in  FIG. 31 , a window in  FIG. 32  is displayed. When the user wants to change the contents of a mail message to be forwarded, he or she presses a “change” button  888 ; when the user wants to send a mail message without change, he or she presses a “send without change” button  889 . When the user has pressed the “send without change” button  889 , a mail message is sent on the basis of the forwarding destination and method set in  FIG. 30  and the source set in  FIG. 31 . 
   When the user has pressed the “change” button  888  in  FIG. 32 , a window in  FIG. 33  is displayed. On the window in  FIG. 33 , the user can edit the contents of a mail message to be forwarded. An input field  890  displays the contents of “Subject” of a mail message, an input field  891  displays mail body text, and the user can edit the contents based on them. The contents (Subject) of the input field  890  are used as “Subject” of mail messages including a mail message that notifies of the URL, and a mail message to a portable terminal, and are also used as the title of a FAX cover page. Since a field  892  displays an attached file, the user can confirm the attached file. By pressing a delete button  893 , the user can choose not to send the attached file. Upon pressing the delete button  893 , a window in  FIG. 33  without the fields  892  and  893  is displayed. When the user has pressed a send button  894 , the results edited in the input fields  890  and  891 , and the attached file displayed in the field  892  are sent on the basis of the forwarding destination and method set in  FIG. 30  and the source set in  FIG. 31 . 
   Since the forwarding method has been described, a sequence for creating new contents to be sent will be explained below. When the user has pressed a new message button  832  in  FIG. 28 , a window in  FIG. 34  is displayed. The window in  FIG. 34  is used for the same purpose as in  FIG. 30  upon forwarding, i.e., is used to designate a sending destination and method. Unlike in  FIG. 30 ,  FIG. 34  has no designation items associated with an attached document. 
   When the user has pressed an OK button  921  in  FIG. 34 , the window in  FIG. 31  is displayed. Since the roles and actions of items on the window shown in  FIG. 31  have already been explained, a description thereof will be omitted. By pressing the OK button  887 , a window in  FIG. 35  is displayed. The window in  FIG. 35  is used to input mail contents. In  FIG. 35 , input fields  925  and  926  for Subject and body text are prepared, and the user inputs them. The contents of the Subject input field  925  are used as Subject of mail messages including a mail message that notifies of the URL, and a mail message to a portable terminal, and are also used as the title of a FAX cover page. By pressing a send button  927 , the contents input to the input fields  925  and  926  are sent on the basis of the sending destination and method set in  FIG. 34  and the source set in  FIG. 31 . 
   Use of an interactive conversion service using the forward and new button displayed on the Web has been explained. In this embodiment, only an interactive service via the Web server has been explained. However, the aforementioned interactive conversion service can be implemented in a Web server for portable terminals, a dedicated terminal, an automatic answering service of a telephone, and the like. 
   &lt;Data Display on Portable Terminal Compatible Web&gt; 
   Data is displayed using a Web browser on a portable terminal by either an automatic conversion service or interactive conversion service. The interactive conversion service is provided by pressing the forward button  840  in  FIG. 29  or the new message button  832  in  FIG. 28 , and by selecting forwarding or sending of data to a portable terminal in  FIG. 30  or  34 . 
   If the user checks the check box  859  in  FIG. 30  and inputs appropriate information in the input fields  860  to  862 , a Mark Up language that can be displayed by a portable terminal is determined by looking up the portable terminal performance table  406   j , and a file is converted into an appropriate format using an appropriate conversion module. The converted file is forwarded to the Web server  600 , and a mail message that describes the URL is forwarded to the mail address entered in the input field  863 . Furthermore, if the user checks a check box  864  in  FIG. 30 , an image format which can be displayed by a portable terminal specified by the portable terminal type, carrier name, and model number input to the input fields  860  to  862  is checked by looking up the portable terminal performance table  406   j . An image attached to a mail message is converted into that image format by an appropriate conversion module, and the converted image file is sent to the Web server so that the image is browsed from a Mark Up language obtained by converting body text as in  FIG. 29 . Likewise, if the user checks a check box  865  in  FIG. 30 , a summary of a wordprocessor document is displayed after body text. 
   If the user checks a check box  906  in  FIG. 34  and inputs appropriate information in input fields  907  to  909 , a Mark Up language that can be expressed by that portable terminal is determined by looking up the portable terminal performance table  406   j , and a file is converted into an appropriate format using an appropriate conversion module. The converted file is forwarded to the Web server  600 , and a mail message that describes the URL is forwarded to the mail address entered in an input field  910 . 
   The interactive conversion service has been explained. An automatic conversion service will be described below. 
   When a check box  805  in  FIG. 27  is checked, a Web page compatible to the portable terminal is prepared in the Web server  600 . A Mark Up language which can be displayed by a portable terminal specified by the portable terminal type, carrier name, and model number registered in the user portable terminal information table  406   d  is checked by looking up the portable terminal performance table  406   j , and mail body text is converted to that language by an appropriate conversion module. If a check box  806  is checked in addition to the check box  805 , an image format which can be displayed by a portable terminal specified by the portable terminal type, carrier name, and model number in the user portable terminal information table  406   d  is checked by looking up the portable terminal performance table  406   j . Then, an appropriate conversion module is selected, and an image attached to a mail message is converted to the image format that can be displayed by the portable terminal using the selected conversion module. The converted image is provided as a portable terminal compatible Web page together with body text. Likewise, when a check box  807  in  FIG. 27  is checked, a summary of a wordprocessor document is displayed after body text. 
   &lt;Data Display on Portable Terminal&gt; 
   Data is displayed on a portable terminal by either an automatic conversion service or interactive conversion service. The interactive conversion service is provided by pressing the forward button  840  in  FIG. 29  or the new message button  832  in  FIG. 28 , and by selecting a forwarding or sending destination of data to a portable terminal in  FIG. 30  or  34 . 
   When the check box  867  in  FIG. 30  is checked, data is forwarded to the mail address entered in the input field  871 . Furthermore, when a check box  872  is checked, the maximum number of characters that can be displayed on a portable terminal specified by the portable terminal type, carrier name, and model number input to the input fields  868  to  870  is checked by looking up the portable terminal performance table  406   j . As a result, if the number of characters of mail body text to be sent is larger than that maximum number of displayable characters, a conversion module which generates a summary from that text generates a summary of mail body text, and a mail message containing that summary is sent to the mail address entered in the input field  871 . On the other hand, when a check box  873  in  FIG. 30  is checked, an image format and image size that can be displayed on a portable terminal specified by the portable terminal type, carrier name, and model number input to the input fields  868  to  870  is checked by looking up the portable terminal performance table  406   j . An appropriate conversion module converts an image attached to a mail message into a format that the portable terminal can use, and changes the image size of that image to one which can be displayed on the portable terminal. Then, the image is sent to the portable terminal. Likewise, when a wordprocessor document file is attached to a mail message, and a check box  874  in  FIG. 30  is checked, the summary of a wordprocessor document is displayed after body text. 
   When a check box  911  in  FIG. 34  is checked, a mail message is transferred to a mail address entered in an input field  915 . Furthermore, when a check box  916  is checked, the maximum number of characters that can be displayed on a portable terminal specified by the portable terminal type, carrier name, and model number input to input fields  912  to  914  is checked by looking up the portable terminal performance table  406   j . As a result, if the number of characters of mail body text to be sent is larger than that maximum number of displayable characters, a conversion module which generates a summary from that text generates a summary of mail body text, and a mail message containing that summary is sent to the mail address entered in the input field  915 . 
   The interactive conversion serve in “data display on portable terminal” has been explained. An automatic conversion service will be described below. 
   When a check box  810  in  FIG. 27  is checked, a mail message is sent to a portable terminal via the mail server  100 . Furthermore, when a check box  811  in  FIG. 27  is checked, the maximum number of characters that can be displayed on a portable terminal specified by the portable terminal type, carrier name, and model number registered in the user portable terminal information table  406   d  in  FIG. 11  is checked by looking up the portable terminal performance table  406   j . As a result, if the number of characters of mail body text to be sent is larger than that maximum number of displayable characters, a conversion module which generates a summary from that text generates a summary of mail body text, and a mail message containing that summary is sent. 
   When a check box  812  in  FIG. 27  is checked, an image format and image size that can be displayed by a portable terminal specified by the portable terminal type, carrier name, and model number registered in the user portable terminal information table  406   d  in  FIG. 11  is checked by looking up the portable terminal performance table  406   j . An appropriate conversion module converts an image attached to a mail message into that image format and image size, and sends the image to the specified portable terminal. Likewise, when a check box  813  in  FIG. 27  is checked, a summary of a wordprocessor document is displayed after body text. If the check boxes  804 ,  809 , and  821  in  FIG. 27  are checked, when a mail message is uploaded to the Web server  600  or a FAX document is sent via the FAX server  650 , a mail message which describes it is sent to the portable terminal. 
   &lt;Data Display (Output) by FAX&gt; 
   Data is displayed (output) via FAX by either an automatic conversion service or interactive conversion service. The interactive conversion service is provided by pressing the forward button  840  in  FIG. 29  or the new message button  832  in  FIG. 28 , and by selecting forwarding or sending of data to FAX in  FIG. 30  or  34 . 
   When one of check boxes  876 ,  878 , and  879  in  FIG. 30  is checked, a corresponding one of body text, an attached image, and attached wordprocessor document is sent via FAX to the FAX number input in the input field  877 . The number of pages to be sent via FAX is adjusted to fall within the FAX allowable page count designated in the input field  880  in  FIG. 30 . Note that each FAX document is appended a cover page indicating the sending source set in  FIG. 31 . 
   When a check box  918  in  FIG. 34  is checked, the contents input in  FIG. 35  are sent via FAX to the FAX number input in an input field  919 . Also, the number of pages of a FAX document is adjusted to fall within the FAX allowable page count designated in an input field  920  in  FIG. 34 . Note that each FAX document is appended a cover page indicating the sending source set in  FIG. 31 . 
   The interactive conversion service in “data display (output) by FAX” has been explained. An automatic conversion service will be described below. 
   When one of the check boxes  815 ,  816 , and  817  in  FIG. 27  is checked, a corresponding one of body text, an attached image, and attached wordprocessor document is sent via FAX. A destination at this time is specified by the FAX number of one of the home, office, and portable terminal designated in the user conversion setup table  406   e , one of the FAX numbers registered in the user home information table  406   b , user office information table  406   c , and user portable terminal information table  406   d  is selected in accordance with a setup which is designated using the menu  818  and is stored in the user conversion setup table  406   e . Also, the number of pages of a FAX document is adjusted to fall within the FAX allowable page count which is designated in the field  819  and is stored in the user conversion setup table  406   e . Note that each FAX document is appended a cover page which indicates, as a destination, information of the address or the like stored in the user home information table  406   b , user office information table  406   c , or user portable terminal information table  406   d , in correspondence with the location which is designated using the pull-down menu  818  and is stored in the user conversion setup table  406   e.    
   &lt;Registration of Other Sites Associated with Conversion Service&gt; 
     FIGS. 36 to 39  show windows of a management tool, which can be accessed by only a site administrator. Using the windows in  FIGS. 36 to 39 , the site administrator inputs information of a net mail service site, directory service site, and conversion service site other than the self site. 
     FIG. 36  shows a window used to register basic information of a service company that manages one of a net mail service site, directory service site, and conversion service site. When the administrator fills input fields  930  to  936  with information as needed, and presses (clicks) an OK button  937 , information of the company that manages a service site is registered in the service company table  406   g.    
     FIG. 37  shows a window used to register basic information of one of a net mail service site, directory service site, and conversion service site. The administrator selects the site management company, which is input in advance using  FIG. 36 , from a pull-down menu  941 , inputs the site name, the URL of CGI that launches the judgment module of that site, and a management mail address in input fields  940 ,  942 , and  943 , and presses (clicks) an OK button  944 . Then, the site information can be registered in the service site table  406   h . Note that the management mail address input in the input field  943  will be described in detail later. 
     FIG. 38  shows a window used to register conversion module information. The administrator selects one of other sites, which are input using  FIG. 37  in advance, or the self site from a pull-down menu  950 , inputs conversion module information in input fields  951  to  958 , and presses (clicks) an OK button  959 . Then, the conversion module information can be registered in the conversion module table  406   f . When the conversion module is present in that site, the name of the conversion module is described as a full path in the input field  951 ; when the conversion module is present in another site, that field can be blank. Since a compatibility level indicates compatibility of the conversion module, the administrator can evaluate and determine it using a common evaluation criterion. As for a price, the administrator can input an arbitrary price if the conversion module is present in the self site, or a price designated by a site manager if the conversion module is present in another site. When the conversion module is registered in the table  406   f , an ID to be stored in a conversion module ID of the conversion module table  406   f  is issued. The conversion module ID is a numeral or character string that uniquely specifies the conversion module. 
     FIG. 39  shows a window used to designate the order in which directory services are used. The administrator selects one of sites, which are input in advance using  FIG. 37 , from each of pull-down menus  960 ,  961 , and  962 , and presses (clicks) an OK button  963 . Then, the directory service sites used and their priority levels are input to the use directory service table  406   i . The site designated using the menu  960  is input to the use directory service table  406   i  as a site with priority=1, and the sites input using menus  961  and  962  are similarly registered to have priority=2 and 3, respectively. In  FIG. 39 , a maximum of three directory service sites can be registered. However, four or more sites may be registered. 
   &lt;Site Registration Content Verification Service&gt; 
   As described above, there are three use modes of a conversion module, i.e., a case wherein a conversion module in the self site is used, a case wherein a conversion module in a site other than the self site is directly used, and a case wherein a conversion module in a site other than the self site is used via a directory service. If the registration contents of conversion modules are defective, not only a problem in the self site but also a problem in, e.g., accounting may occur. The site registration content verification service is a function of minimizing such risk. 
   Upon registration of a conversion module, inputs are made using the window in  FIG. 38 . That is, an appropriate one of the already registered conversion service sites is selected from the pull-down menu  950 , and appropriate contents are input to the input fields  951  to  958 . Upon pressing (clicking) the OK button  959 , the setup module  500  ( 500   b ) stores the conversion module information in the conversion module table  406   f . At this time, a service validity flag is set to be “false”, and the use count and success count are respectively set to be “0”. 
   Furthermore, the setup module  500  ( 500   b ) reads out a mail address from the service site table  406   h , and sends an XML file by mail to this address via the mail server  100  ( 100   b ). This XML file describes items of the input format (MIME), input format (extension), output format (MIME), output format (extension), output format (unique), and price, which are stored in the conversion module table  406   f .  FIG. 50A  shows an example of such XML file. Upon sending this mail message, the mail server  100  ( 100   b ) creates a new mail account, and uses that mail account in a Reply-To header of that mail message. 
   Upon receiving the mail message, the mail server of the conversion service site or directory service site passes that mail message to the setup module  500   a  ( 500   b ,  500   c ). The setup module  500   a  ( 500   b ,  500   c ) parses the XML file to compare it with the contents of the conversion module table  406   f . If their contents match, the setup module returns a mail message to the Reply-To address. The contents of this mail message are written in XML. This XML file describes the conversion module ID in the conversion module table  406   f  in the conversion service site or directory service site.  FIG. 51A  shows an example of this XML file. 
   Upon receiving the mail message from the conversion service site or directory service site, the mail server erases the mail address used to receive this mail message, and passes the mail message to the setup module  500  ( 500   b ). The setup module  500  ( 500   b ) sets the service validity flag in the conversion module table  406   f  to be “True”, and inputs the conversion service side conversion module ID. If the conversion module ID described in the XML file of that mail message, and the service site ID indicating the service site that originated the mail message match the conversion service site side conversion module ID and service site ID of another conversion module registered in the conversion module table  406   f , the setup module does not update the corresponding items of the conversion module table  406   f , and re-sends a mail message shown in  FIG. 50B . If the setup module is informed of the conversion module ID, which is not already registered, as shown in  FIG. 51A , it inputs information to the corresponding items in the conversion module table  406   f , as described above. If the setup module receives the already registered conversion module ID again, it sends a mail message in  FIG. 50B . If the setup module receives a message indicating that no corresponding conversion module is found in the conversion service site or directory service site, as shown in  FIG. 51B , it erases the corresponding items from the conversion module table  406   f.    
   In this embodiment, XML files are sent by mail to provide the site registration content verification service. However, this method is merely an example. A method using a unique protocol, method using another versatile protocol, and the like may be used. 
   In the following description, the conversion module table  406   f  is searched for a conversion module in some steps. In this case, since such search is made under the condition that the service validity flag=“True”, confirmation of the service validity flag is not cited. 
   &lt;Automatic Mail Conversion Service&gt; 
   Mail conversion services that allow to display data on a Web, portable terminal, and FAX include a service which is automatically provided when a mail message has arrived at the mail server  100 , and a service which is made by the user interactively via the Web server  600  or a phone. The mechanism of the automatic mail conversion service will be explained below.  FIG. 40  is a flow chart showing the processing after the mail server receives a mail message and passes that mail message to the judgment module  200 . When a plurality of documents are attached to a mail message, all attached documents undergo the process to be described below in the order they are attached in individual steps A, B, C, and D. 
   If the mail message has multipart Content-Type, the mail message is split using a boundary into individual parts (step S 300 ). If a conversion module that can decode encoded data (normally, Base64, Uuencode, or the like) given by Content-Transfer-Encoding is available, that encoded data is decoded (step S 305 ). Then, conversion processes for individual media shown in  FIG. 41A  to  FIG. 44  are executed. That is, if that mail message is to be displayed on a Web, the process shown in  FIGS. 41A to 41D  starts from step S 310 ; if the mail message is to be displayed on a Web compatible to a portable terminal, the process shown in  FIGS. 42A to 42D  starts from step S 400 ; if the mail message is to be forwarded to FAX, the process shown in  FIGS. 43A to 43D  starts from step S 500 ; or if the mail message is to be displayed on a portable terminal using its mail function, the process shown in  FIG. 44  starts from step S 600 . Note that display on the portable terminal using its mail function includes a message indicating that the mail message is uploaded to the Web server, a message indicating that the mail message is forwarded to FAX, and the like in addition to display of the mail contents. 
   &lt;&lt;Conversion to Data Displayable on Web&gt;&gt; 
     FIGS. 41A to 41D  are flow charts showing the process for generating data to be displayed on a Web. Since body text does not require any conversion, conversion is required for an image, wordprocessor document, or the like attached to a mail message. If the user conversion setup table  406   e  includes a setup for displaying an image on a Web (step S 311 ), it is checked based on Content-Type and name extension if mail data contains an image, and it is also checked if the format of that image must be converted (step S 312 ). If an image is contained, and image format conversion is required, the Content-Type and name extension of the image are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for appropriate conversion modules for converting this image format into JPEG (step S 313 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. In procedure F, an optimal one of a plurality of appropriate conversion modules is selected on the basis of the conversion module select criterion stored in the user conversion setup table  406   e  and the compatibility level, price, and stability (defined by dividing the success count by the use count) stored in the conversion module table  406   f , as shown in  FIG. 46 . 
   Referring to  FIG. 46 , it is checked if two or more appropriate conversion modules are registered in the conversion module table  406   f . If only one conversion module is available, that conversion module is determined as one to be used (steps S 700  and S 709 ). On the other hand, if two or more appropriate conversion modules are found, the set conversion module select criterion is acquired by looking up the user conversion setup table  406   e . If only one conversion module with the highest select criterion set in the table is found, that conversion module is determined as one to be used (steps S 702  and S 709 ). 
   If a plurality of conversion modules with the highest select criterion set in the table are found in step S 702 , “stability”, “price”, and “compatibility level” are checked individually to narrow down candidates. In this embodiment, “stability”, “price”, and “compatibility level” are checked in the order named, but this order is not limited to that of this embodiment. Also, this order may be set by the user. 
   If only one of conversion modules extracted in step S 702  has the highest stability, that conversion module is determined as the one to be used (steps S 703  and S 709 ). If a plurality of conversion modules still remain after step S 703 , conversion modules with the lowest price are extracted. If only one conversion module is extracted, that module is determined as the one to be used (steps S 704  and S 709 ). If a plurality of conversion modules still remain after step S 704 , conversion modules with the highest compatibility level are extracted. If only one conversion module is extracted, that module is determined as the one to be used (steps S 705  and S 709 ). 
   As a result of narrowing down the candidates, if a plurality of conversion modules still remain, a conversion module in the identical site is preferentially determined to be the one to be used (steps S 706  and S 708 ). If a conversion module in the identical site is not found, a conversion module with the smallest conversion module ID is set as the one to be used (steps S 706  and S 707 ). If a plurality of conversion modules are found in the identical site at the time of step S 706 , a conversion module with the smallest ID of those in the identical site is determined as the one to be used in step S 707 . 
   If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 322 ), it is checked if the selected conversion module is present within the site (step S 323 ). If YES in step S 323 , a conversion instruction is sent to the selected conversion module (step S 326 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 324 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in G (see  FIG. 47 ). That is, if any error such as a network error, abnormal termination of the conversion module, or the like has occurred (step S 721 ), only the use count in the conversion module table  406   f  is incremented (step S 723 ); otherwise, both the use count and success count in the conversion module table  406   f  are incremented (step S 722 ). 
   Upon completion of updating (G) of the stability, an accounting process is executed. If conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 325 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 327 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  (step S 313 ), or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 322 ), steps S 314  to S 317  and S 321  are executed to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 314 ), an inquiry is sent to the service site in the order of priority (step S 316 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 317 , S 321 , and S 315 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 315 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 318 ), a conversion instruction is sent to the corresponding directory service site (step S 319 ). After conversion, the price of the conversion module (to be described later) is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 320 ). On the other hand, if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 318 ), conversion is skipped. 
   If the user sets to display a wordprocessor document on a Web (step S 331 ), it is checked based on Content-Type and name extension if mail data contains a wordprocessor document (step S 332 ). By comparing the Content-Type and name extension of the wordprocessor document with the input format (MIME) and input format (extension) in the conversion module table  406   f , an appropriate conversion module used to convert the format of this wordprocessor document to HTML is searched for (step S 333 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 342 ), it is checked if the selected conversion module is present within the site (step S 343 ). If YES in step S 343 , a conversion instruction of that wordprocessor document is sent to the selected conversion module (step S 346 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 344 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in the above process G (see  FIG. 47 ), and an accounting process is then executed. If conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 345 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 347 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  in step S 333 , or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  in step S 342 , the flow advances to step S 334  to execute steps S 334  to S 337  and S 341  so as to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 334 ), an inquiry is sent to the service site in the order of priority (step S 336 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 337 , S 341 , and S 335 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 335 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 338 ), a conversion instruction is sent to the corresponding directory service site (step S 339 ). After conversion, the price of the conversion module (to be described later) is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 340 ). On the other hand, if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 338 ), conversion is skipped. 
   Individual converted parts or non-converted parts are arranged in the order in which they appear in the original mail, and an HTML header obtained by bounding the contents of “Subject” by title tags is appended (step S 351 ), thus generating a Web page. The obtained Web page is stored in the net database  400  (step S 352 ). 
   Note that inquiring of the directory service site is implemented by passing an XML file via HTTP in this embodiment.  FIG. 52  shows an example of an XML file indicating an inquiry. The XML file describes MIME and extensions of the input and output formats of a required conversion module, which are compared with those in the conversion module table  406   f  in the directory service site. The XML file also describes contents to be emphasized upon selecting a conversion module, and such contents are used to select one conversion module if a plurality of conversion modules that meet the condition are found (process F to be described later using  FIG. 48 ). Using an XML file shown in  FIG. 53 , data of the found conversion module is passed (step S 751 ). 
   This XML file contains id which is used as an argument upon sending a conversion request to the directory service site, in addition to the price of the conversion module. Note that this id is the same as the conversion module ID contained in the conversion module table  406   f . Note that this embodiment implements using XML and HTTP, but such implementation is merely an example and there are no portions which depend on XML and HTTP. It is possible to implement using a unique protocol or another versatile protocol. 
   In the process shown in  FIGS. 41A to 41D , if it is determined in step S 318  (S 338 ) that the use fee of a module found by the process in steps S 314  to S 317  and S 321  (S 334  to S 337  and S 341 ) is not zero, and use of a pay conversion module is not permitted, conversion is skipped. Alternatively, steps S 314  to S 317  and S 321  (S 334  to S 337  and S 341 ) may be executed to search for a directory service site with lower priority for a conversion module. 
   &lt;&lt;Conversion to Web Page Compatible to Portable Terminal&gt;&gt; 
     FIGS. 42A to 42D  are flow charts showing a sequence for generating a Web page compatible to a portable terminal. In order to detect a Mark Up language that a portable terminal uses, the portable terminal performance table  406   j  is looked up to find a Mark Up language of a portable terminal specified by the portable terminal type, carrier name, and model number in the user portable terminal information table  406   d  (step S 401 ). Since body text does not require any conversion, conversion is required for an image, wordprocessor document, or the like attached to a mail message. 
   If the user conversion setup table  406   e  includes a setup for displaying an image on a Web compatible to the portable terminal (step S 411 ), it is checked based on Content-Type and name extension if mail data contains an image (step S 412 ). If an image is contained, the portable terminal performance table  406   j  is looked up to find an image format that can be displayed by the portable terminal specified by the portable terminal type, carrier name, and model number in the user portable terminal information table  406   d  (step S 413 ). Then, the Content-Type and name extension of the image are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for appropriate conversion modules for converting this image into an appropriate image format (step S 414 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 423 ), it is checked if the selected conversion module is present within the site (step S 424 ). If YES in step S 424 , a conversion instruction is sent to the selected conversion module (step S 427 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 425 ). Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in G (see  FIG. 47 ), and an accounting process is then executed. That is, if conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 426 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 428 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  in step S 414 , or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  in step S 423 , steps S 415  to S 418  and S 422  are executed to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 415 ), an inquiry is sent to the service site in the order of priority (step S 417 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 418 , S 422 , and S 416 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 416 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 419 ), a conversion instruction is sent to the corresponding directory service site (step S 420 ). 
   After conversion, the price of the conversion module reported from the directory service site is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 421 ). On the other hand, if it is determined in step S 419  that the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e , conversion is skipped. 
   Upon completion of the process for the image attached to the mail message, a process for a wordprocessor document attached to that mail message is then executed. 
   If the user sets to display a wordprocessor document on a Web compatible to a portable terminal, i.e., if a setup is made to display the summary of the wordprocessor document on the portable terminal compatible Web (step S 431 ), it is checked based on Content-Type and name extension if mail data contains a wordprocessor document (step S 432 ). If the wordprocessor document is contained, the Content-Type and name extension of the wordprocessor document are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for an appropriate conversion module used to convert the format of this wordprocessor document to the Mark Up language found in step S 401  (step S 433 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 442 ), it is checked if the selected conversion module is present within the site (step S 443 ). If YES in step S 443 , a conversion instruction of that wordprocessor document is sent to the selected conversion module (step S 446 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction of the wordprocessor document is sent to the judgment module of that site (step S 444 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in G (see  FIG. 47 ), and an accounting process is then executed. That is, if conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 445 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 447 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  (step S 433 ), or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 442 ), steps S 434  to S 437  and S 441  are executed to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 434 ), an inquiry is sent to the service site in the order of priority (step S 436 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 437 , S 441 , and S 435 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 435 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 438 ), a conversion instruction is sent to the corresponding directory service site (step S 439 ). After conversion, the price of the conversion module reported from the directory service site is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 440 ). On the other hand, if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 438 ), conversion is skipped. 
   Individual converted parts or non-converted parts are arranged in the order in which they appear in the original mail, and a header unique to the Mark Up language, which contains the contents of “Subject” as a title is appended (step S 451 ), thus generating a Web page compatible to the portable terminal. The obtained Web page is stored in the net database  400  (step S 452 ). 
   In this embodiment, it is assumed that a Web browser on the portable terminal can process a sufficiently large file size. However, even if the file size that the Web browser can process is limited, the file may be divided into a plurality of files which can be joined via hyperlinks. Hence, the above assumption can preserve universality. 
   In the process shown in  FIGS. 42A to 42D , if it is determined in step S 419  (S 438 ) that the use fee of a module found by the process in steps S 415  to S 418  and S 422  (S 434  to S 437  and S 441 ) is not zero, and use of a pay conversion module is not permitted, conversion is skipped. Alternatively, steps S 415  to S 418  and S 422  (S 434  to S 437  and S 441 ) may be executed to search for a directory service site with lower priority for a conversion module. 
   &lt;&lt;Conversion to Data That Can Be Sent to FAX&gt;&gt; 
     FIGS. 43A to 43D  are flow charts showing a process for generating display data to be sent via FAX. If the user sets to send mail body text via FAX (step S 501 ), body text is converted into a CCITT FAX format by a conversion module for laying out and rendering body text and then CCITT FAX encoding that text (step S 502 ). 
   If the user conversion setup table  406   e  includes a setup for sending an image via FAX (step S 511 ), it is checked based on Content-Type and name extension if mail data contains an image (step S 512 ). If an image is contained, the Content-Type and name extension of the image are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for appropriate conversion modules for converting this image into the CCITT FAX (step S 513 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 522 ), it is checked if the selected conversion module is present within the site (step S 523 ). If YES in step S 523 , a conversion instruction is sent to the selected conversion module (step S 526 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 524 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in G (see  FIG. 47 ), and an accounting process is then executed. If conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 525 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 527 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  (step S 513 ), or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 522 ), steps S 514  to S 517  and S 521  are executed to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 514 ), an inquiry is sent to the service site in the order of priority (step S 516 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 517 , S 521 , and S 515 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 515 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 518 ), a conversion instruction is sent to the corresponding directory service site (step S 519 ). After conversion, the price of the conversion module reported from the directory service site is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 520 ). On the other hand, if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 518 ), conversion is skipped. 
   Furthermore, if the user sets to forward a wordprocessor document to FAX (step S 531 ), it is checked based on Content-Type and name extension if mail data contains a wordprocessor document (step S 532 ). If the wordprocessor document is contained, the Content-Type and name extension of the wordprocessor document are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for an appropriate conversion module used to convert the format of this wordprocessor document to the CCITT FAX format (step S 533 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 542 ), it is checked if the selected conversion module is present within the site (step S 543 ). If YES in step S 543 , a conversion instruction of that wordprocessor document is sent to the selected conversion module (step S 546 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 544 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in the above process G (see  FIG. 47 ), and an accounting process is then executed. If conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 545 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 547 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  in step S 533 , or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  in step S 542 , the flow advances to step S 534  to execute steps S 534  to S 537  and S 541  so as to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 534 ), an inquiry is sent to the service site in the order of priority (step S 536 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 537 , S 541 , and S 535 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 535 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 538 ), a conversion instruction is sent to the corresponding directory service site (step S 539 ) After conversion, the price of the conversion module reported from the directory service site is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 540 ). On the other hand, if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 538 ), conversion is skipped. 
   Individual converted parts are arranged in the order in which they appear in the original mail to generate a document to be sent, and the number of pages of the document is checked (step S 551 ). If the number of pages is equal to or smaller than the number of pages that the user designated in the FAX allowable output page count ( 819 ) in  FIG. 27  (registered in the user conversion setup table  406   e ) (step S 552 ), a cover page indicating the address of user&#39;s choice as a FAX forwarding destination is generated, and is attached to the head of the generated document (step S 553 ). On the other hand, if the number of pages of the document is larger than the number of pages that the user designated in the FAX allowable output page count ( 819 ) in  FIG. 27 , the flow advances to step S 554  to delete some pages from the document generated in step S 551  in turn from the last page, so that the number of pages of the document falls becomes equal to the FAX allowable output page count. Then, a cover page which contains a message indicating that the number of pages to be sent is limited according to user&#39;s designation, and which indicates the address of user&#39;s choice as a FAX forwarding destination is generated, and is appended to the head of the document, the number of pages of which has been adjusted (step S 554 ). The document obtained in step S 553  or S 554  is sent to a facsimile device designated by the user via the FAX server  650  (step S 555 ) 
   &lt;&lt;Convert to Data Displayable on Portable Terminal&gt;&gt; 
     FIG. 44  is a flow chart showing a process for generating data to be displayed on a portable terminal. When data is uploaded to the Web server or a FAX document is sent, text of a message to be sent to the portable terminal is generated. That is, it is checked if “notify by mail when Web page is uploaded to Web server” is set in the user conversion setup table  406   e  (step S 601 ). If YES in step S 601 , message text indicating that data is uploaded to the Web server is generated (step S 602 ). Likewise, it is checked if “notify by mail when page compatible to portable terminal is uploaded to Web server” is set in the user conversion setup table  406   e  (step S 603 ). If YES in step S 603 , message text indicating that data is uploaded to the Web server is generated (step S 604 ). It is then checked if “notify of destination if FAX is sent” is set in the user conversion setup table  406   e  (step S 605 ). If YES in step S 605 , message text indicating that the FAX is sent, and FAX destination is generated (step S 606 ). The message text contents generated in these steps S 602 , S 604 , and S 606  are arranged in turn, and the number of characters of total text is checked (step S 607 ). 
   It is checked if “forward to portable terminal=ON” is set in the user conversion setup table  406   e  (step S 608 ). If YES in step S 608 , individual conversion processes, which will be explained later using the flow charts of  FIGS. 45A to 45D , are executed. After that, individual converted parts and parts which need not be converted are appended in an order in which they appear in the original mail, and message text generated in step S 607  is appended to the head, thus generating a document to be sent to the portable terminal (step S 609 ). The obtained document is sent to the portable terminal designated by the user via the mail server  100  (step S 610 ). 
   Process E executed when it is determined in step S 608  that “forward to portable terminal=ON” is set will be described in detail below. When “forward to portable terminal=ON” is set, the control enters the process in  FIGS. 45A to 45D  to execute individual conversion processes required to display a mail message on the portable terminal. 
   As for body text, the portable terminal performance table  406   j  is looked up to find the maximum number of characters that can be displayed on the portable terminal specified by the portable terminal type, carrier name, and model number registered in the user portable terminal information table  406   d , and it is checked if the number of characters of mail body text is larger than a value obtained by subtracting the number of characters of the message text detected in step S 607  from the maximum number of displayable characters (step S 621 ). If YES in step S 621 , it is checked based on the setup contents of the user conversion setup table  406   e  if a summary of body text is to be generated (step S 622 ). If the user sets to generate the summary, a conversion module for generating a summary of body text generates a summary of mail body text (step S 624 ). On the other hand, if the user sets not to generate a summary, a conversion module which cuts off a character string of the mail body text to fall within the maximum number of displayable characters of the portable terminal cuts off a character string (step S 623 ). 
   If the user conversion setup table  406   e  includes a setup for displaying an image on the portable terminal (step S 631 ), it is checked based on Content-Type and name extension if mail data contains an image (step S 632 ). If an image is contained, the portable terminal performance table  406   j  is looked up to find an image format that can be displayed by the portable terminal specified by the portable terminal type, carrier name, and model number in the user portable terminal information table  406   d  (step S 633 ). Then, the Content-Type and name extension of the image are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for appropriate conversion modules for converting this image into an appropriate image format (step S 634 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 643 ), it is checked if the selected conversion module is present within the site (step S 644 ). If YES in step S 644 , a conversion instruction is sent to the selected conversion module (step S 647 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 645 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in G (see  FIG. 47 ), and an accounting process is then executed. If conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 646 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 648 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  (step S 634 ), or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 643 ), steps S 635  to S 638  and S 642  are executed to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 635 ), an inquiry is sent to the service site in the order of priority (step S 637 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 638 , S 642 , and S 636 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 636 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 639 ), a conversion instruction is sent to the corresponding directory service site (step S 640 ). After conversion, the price of the conversion module reported from the directory service site is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 641 ). On the other hand, if it is determined in step S 639  that the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e , conversion is skipped. 
   Also, if the user sets to display the summary of a word processor document on the portable terminal (step S 651 ), it is checked based on Content-Type and name extension if mail data contains a wordprocessor document (step S 652 ). If the wordprocessor document is contained, the Content-Type and name extension of the wordprocessor document are compared with the input format (MIME) and input format (extension) in the conversion module table  406   f  to search for an appropriate conversion module used to convert the format of this wordprocessor document to the summary (step S 653 ). 
   If appropriate conversion modules are found, one optimal conversion module is selected via procedure F. If the use price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 662 ), it is checked if the selected conversion module is present within the site (step S 663 ). If YES in step S 663 , a conversion instruction is sent to the selected conversion module (step S 666 ). On the other hand, if the selected conversion module is present in a site other than the self site, a conversion instruction is sent to the judgment module of that site (step S 664 ). 
   Upon completion of conversion by the conversion module irrespective of the site location, the stability is updated in G (see  FIG. 47 ), and an accounting process is then executed. If conversion was made by the conversion module outside the site, the price in the conversion module table  406   f  is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 665 ). On the other hand, if the conversion was made by the conversion module in the site, the price in the conversion module table  406   f  is added to only the accounting record in the user information table  406   a  (step S 667 ). 
   On the other hand, if no appropriate conversion module is registered in the conversion module table  406   f  (step S 653 ), or if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 662 ), steps S 654  to S 657  and S 661  are executed to select an appropriate conversion module from the directory service sites registered in the use directory service table  406   i.    
   The number of directory service sites registered in the use directory service table  406   i  is stored in a variable i (step S 654 ), an inquiry is sent to the service site in the order of priority (step S 656 ), and this process is repeated until a directory service site in which an appropriate conversion module is registered is found (steps S 657 , S 661 , and S 655 ). If no appropriate conversion module is found even after inquiries were sent to all directory service sites (i=0 in step S 655 ), conversion is skipped. 
   If an appropriate conversion module is found, and the price of the conversion module is zero (by looking up the conversion module table  406   f ) or use of a pay conversion module is permitted (by looking up the user conversion setup table  406   e ) (step S 658 ), a conversion instruction is sent to the corresponding directory service site (step S 659 ). After conversion, the price of the conversion module reported from the directory service site is added to the accounting record in the user information table  406   a , the scheduled payment record in the service company table  406   g , and the site-dependent scheduled payment record in the service site table  406   h  (step S 660 ). On the other hand, if the price of the conversion module to be used is not zero and use of a pay conversion module is not permitted in the user conversion setup table  406   e  (step S 658 ), conversion is skipped. 
   In the process shown in  FIGS. 45A to 45D , if it is determined in step S 639  (S 658 ) that the use fee of a module found by the process in steps S 635  to S 638  and S 642  (S 654  to S 657  and S 661 ) is not zero, and use of a pay conversion module is not permitted, conversion is skipped. Alternatively, steps S 635  to S 638  and S 642  (S 654  to S 657  and S 661 ) maybe executed to search for a directory service site with lower priority for a conversion module. 
   The functions of the judgment module of the net mail service site in the automatic conversion service have been explained. The functions of the judgment module in the directory service site will be explained below. As has already been described, there are two roles that the judgment module of the directory service site must play: (1) to fulfill the search request of a conversion module from the net mail service site, and (2) to fulfill the format conversion request. These functions will be described in detail below using  FIG. 48 . 
   If a request from the net mail service site is a search request of a conversion module (step S 750 ), the judgment module receives an XML file that describes the input and output file formats of a required conversion module, and contents to be emphasized upon selecting that conversion module. Hence, using such information, process F ( FIG. 46 ) is executed to select the best conversion module from those registered in the conversion module table  406   f . Information (including compatibility level, price, stability, and conversion module ID) of this conversion module is passed as an XML file to the judgment module of the net mail service site (steps S 750  to S 751 ). 
   If a request from the net mail service site is a file conversion request (step S 750 ), a conversion request is issued by designating the conversion module ID, as described above. The conversion module table  406   f  in the directory service site is looked up to find a conversion module site corresponding to this ID and the ID in that conversion module site, and a conversion request is sent to the conversion module site (step S 752 ). If an error has occurred before the conversion result is obtained (step S 753 ), an error is returned to the net mail service site (step S 754 ), and the use count in the conversion module table  406   f  is incremented (step S 755 ). 
   If a normal result is obtained, the conversion result is returned to the net mail service site (step S 756 ), and both the use count and success count in the conversion module table  406   f  are incremented (step S 757 ). Then, an accounting process is executed, i.e., the price in the conversion module table  406   f  is subtracted from (in case of the module in the mail service site) or added to (in case of the module in the conversion module site) the scheduled payment record in the service company table  406   g  and the site-dependent scheduled payment record in the service site table  406   h  (step S 758 ). 
   The functions of the judgment module in the conversion service site will be described below using  FIG. 49 . If a conversion request is issued from the net mail service site or directory service site, a conversion request is sent to a conversion module corresponding to the conversion module ID (step S 770 ). If an error has occurred before the conversion result is obtained (step S 771 ), an error is returned to the net mail service site or directory service site (step S 772 ), and the use count in the conversion module table  406   f  is incremented (step S 773 ). On the other hand, if a normal result is obtained, the conversion result is returned to the net mail service site or directory service site (step S 774 ), and both the use count and success count in the conversion module table  406   f  are incremented (step S 775 ). Then, an accounting process is executed, i.e., the price in the conversion module table  406   f  is subtracted from the scheduled payment record in the service company table  406   g  and the site-dependent scheduled payment record in the service site table  406   h  (step S 776 ) 
   &lt;Interactive Mail Conversion Service&gt; 
   In the automatic mail conversion service, conversion is made based on the user conversion setups, which are set in advance using  FIG. 27 , and are stored in the user conversion setup table  406   e . As has been described previously, the temporary flag of the use conversion setup table  406   e  used in this case is “False”. On the other hand, in the interactive mail conversion service, user conversion setups are made using  FIG. 30  or  34  immediately before conversion, and are stored in the user conversion setup table  406   e . In this case, the contents of the user conversion setup table  406   e  are substantially the same as that in the automatic conversion service, except that the temporary flag is “True”. In the automatic conversion service, the forwarding destination is selected from those registered in advance in the user home information table  406   b , user office information table  406   c , and user portable terminal information table  406   d . In the interactive conversion service, the forwarding destination set via  FIG. 30  or  34  is used instead. As can be seen from the above description, the automatic and interactive conversion services can use the same flow, and all descriptions using  FIGS. 40 to 49  can be applied to the interactive conversion service. Hence, a description of the interactive conversion service will be omitted. 
   As described above, according to this embodiment, upon receiving information which cannot be expanded and displayed in a terminal environment in which the user receives an e-mail message, the user is informed of summary information and an acquisition method of that information, and information which cannot be expanded and displayed in the user&#39;s environment can be provided to the user in various patterns, thereby greatly improving an e-mail use environment. 
   &lt;Another Embodiment&gt; 
   The objects of the present invention are also achieved by supplying a storage medium, which records a program code of a software program that can implement the functions of the above-mentioned embodiments to the system or apparatus, and reading out and executing the program code stored in the storage medium by a computer (or a CPU or MPU) of the system or apparatus. 
   In this case, the program code itself read out from the storage medium implements the functions of the above-mentioned embodiments, and the storage medium which stores the program code constitutes the present invention. 
   As the storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, DVD, and the like may be used. 
   The functions of the above-mentioned embodiments may be implemented not only by executing the readout program code by the computer but also by some or all of actual processing operations executed by an OS (operating system) running on the computer on the basis of an instruction of the program code. 
   Furthermore, the functions of the above-mentioned embodiments may be implemented by some or all of actual processing operations executed by a CPU or the like arranged in a function extension board or a function extension unit, which is inserted in or connected to the computer, after the program code read out from the storage medium is written in a memory of the extension board or unit. 
   To restate, according to the present invention, the contents of an e-mail message can be forwarded while being converted into a data format corresponding to the performance of an e-mail receiving terminal, and a message indicating that forwarding can be sent to another receiving terminal. 
   As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the claims.