Abstract:
The invention provides a method and system for dynamic downloading of hypertext electronic mail messages. The system includes a mail server for receiving electronic mail messages and their headers, and a mail client for downloading electronic mail messages and their headers from the mail receiver and presenting downloaded electronic mail messages and headers to an operator. The mail client dynamically downloads and presents electronic mail messages responsive to interactive instructions from an operator, preloads and stores electronic mail messages for subsequent presentation to the operator, and organizes electronic mail messages in hypertext sections for selection by and presentation to the operator. The mail server and the mail client cooperate dynamically and interactively to download, so as to present to the operator, electronic mail messages, or portions thereof, linked by hypertext links and possibly including data, audiovisual material, included programs, security features, or other features in addition to text.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to dynamic downloading of hypertext electronic mail messages. 
     2. Description of Related Art 
     Electronic mail is a technique in which messages are composed by a sender, sent from a sending computer, received and stored at a receiving computer, and ultimately presented to a recipient; the sending computer and the receiving computer may be the same computer, or may be different computers which are coupled together using a computer network or other communication link. For example, an operator may use a workstation for composing electronic mail messages and to couple that workstation to the sending computer for sending those electronic mail messages, and to couple the workstation to the receiving computer for receiving electronic mail messages and to use the workstation for reviewing those electronic mail messages. 
     One problem which has arisen in the art is that it can take substantial time to transmit an electronic mail message from the workstation to the sending computer (herein called “uploading” the message) or to transmit an electronic mail message from the receiving computer to the workstation (herein called “downloading” the message). This problem is particularly acute when the electronic mail message is laden with data or graphics, when the communication link (between the workstation and the sending computer or between the workstation and the receiving computer) has relatively low communication bandwidth, or when there are many electronic mail messages to be transmitted. The operator of the workstation perceives substantial transmission time as excessive latency in uploading or downloading electronic mail messages. 
     One method has been to transmit only a part of the electronic mail message for presentation to the operator, such as a header for the message or a first screen display for the message, and to require the operator to request more of the electronic mail message before the remainder is transmitted for presentation. Although this method allows the operator to review at least part of the electronic mail message relatively quickly, it suffers from the drawback that the operator must be present at the workstation to request further information and thus to cause the electronic mail message to be fully transmitted for presentation. 
     A variant of this method is to transmit the entire electronic mail message for immediate presentation to the operator, but to allow the operator to interrupt the transfer, such as with a flow control character, if it is desired to perform another task. Although this method also allows the operator to review at least part of the electronic mail message relatively quickly, it suffers from the drawback that the operator must review only a single electronic mail message at a time, and therefore must wait the full latency for downloading a first electronic mail message before reviewing any part of a second electronic mail message. 
     An aspect of the problem which has arisen in the art is that electronic mail messages are linear sequences of characters, while it is often desirable to transmit information which is organized other than linearly. For example, it is often desirable to transmit information organized as hypertext, such as information presented using HTML (hypertext markup language) or related description languages, and capable of being transmitted using the HTTP (hypertext transfer protocol) or related protocols. When information is so organized, presenting information in the electronic mail message in the order it is transmitted will often be contrary to the purposes of the both the sender and recipient. Rather, the operator will wish to review portions of the electronic mail message in a different order from the order it is transmitted by the sender to the recipient. 
     Accordingly, it would be advantageous to provide a tecnique for downloading electronic mail messages which allows an operator to review at least portions of those electronic mail messages without waiting to download the entire electronic mail message. This advantage is achieved by a method and system according to the present invention in which electronic mail messages and portions thereof are presented to an operator at a workstation while other electronic mail messages or other portions of the same electronic mail message are dynamically downloaded in one or more background tasks and held in storage for later presentation. 
     SUMMARY OF THE INVENTION 
     The invention provides a method and system for dynamic downloading of hypertext electronic mail messages. The system includes a mail server for receiving electronic mail messages and their headers, and a mail client for downloading electronic mail messages and their headers from the mail receiver and presenting downloaded electronic mail messages and headers to an operator. The mail client dynamically downloads and presents electronic mail messages responsive to interactive instructions from an operator, downloads and stores electronic mail messages for subsequent presentation to the operator, and organizes electronic mail messages in hypertext sections for selection by and presentation to the operator. In preferred embodiments, the mail server and the mail client cooperate dynamically and interactively to download, so as to present to the operator, electronic mail messages, or portions thereof, linked by hypertext links and possibly including data, audiovisual material, included programs, security features, or other features in addition to text. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a system for accessing electronic mail messages. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Embodiments of this invention may be used together with inventions described in the following co-pending application, hereby incorporated by reference as if fully set forth herein: 
     application Ser. No. 08/712,586, filed Sep. 13, 1996, in the name of inventor Julien T. Nguyen, titled “Dynamic Preloading of Web Pages”, attorney docket number MWEB-001, assigned to the same assignee. 
     In the following description, a preferred embodiment of the invention is described with regard to preferred process steps and data structures. However, those skilled in the art would recognize, after perusal of this application, that embodiments of the invention may be implemented using a general purpose processor, and that modification of a general purpose processor to implement the process steps and data structures described herein would not require undue invention. 
     SYSTEM FOR ACCESSING ELECTRONIC MAIL MESSAGES 
     FIG. 1 shows a system for accessing electronic mail messages. 
     A system  100  for accessing electronic mail messages comprises a mail server  110 , a communication link  120 , and a mail client  130 . 
     In a preferred embodiment, the mail server  110  comprises a server processor  111  and server storage  112 , with the processor  111  comprising at least one general purpose computer having a computing element, program and data memory. 
     The mail server  110  is disposed for receiving electronic mail messages, and for generating and responding to requests from the mail client  130  in a protocol for transmitting electronic mail messages to the mail client  130 . The protocol is preferably the Simple Mail Transfer Protocol (“SMTP”), but the concepts of the invention are broad enough to apply to other electronic mail protocols and protocols for transferring and presenting information. 
     In a preferred embodiment, the communication link  120  comprises a dynamic link using a network  121  (such as a local area network or a wide area network) or a network of networks (such as an “internet” or an “intranet”). The mail server  110  is coupled to the network using a server local link  122 , such as a T 1  line or other telephone line; similarly, the mail client  130  is coupled to the network using a client local link  123 , such as a telephone line and a modem such as an ISDN modem or a 28.8 Kbps analog modem. Other techniques for coupling the mail server  110  and the mail client  130  to the network  121  are known in the art. 
     The mail client  130  similarly comprises a processor  131  and client storage  132 , with the processor  111  comprising a general purpose processor having a computing element, program and data memory. In a preferred embodiment, preferred process steps and data structures for the page client  130  are specified in the the “Java” computer language. The general purpose processor may comprise any processor disposed to interpret or to compile the “Java” computer language, such as an Intel “Pentium” processor operating at 90 megahertz, having 32 megabytes of program/data memory, operating under control of the Microsoft “Windows 95” operating system, and coupled to 1.0 gigabytes of client storage  132 . 
     In a first preferred embodiment, the mail client  130  comprises an input element  133  and a display element  134 . The input element  133  comprises a keyboard and a pointing device such as a mouse or trackball. The display element  134  comprises a visual display element such as a monitor or a display panel, and an audio display element such as a speaker. 
     In a second preferred embodiment, the mail client  130  does not include both the input element  133  and the display element  134 , but is disposed for coupling to devices for performing those functions and which are supplied by an operator. For example, the mail client  130  may comprise an input port  135  disposed for coupling to the input element  133 , an output port  136  disposed for coupling to the display element  134 , or both. 
     The operator may be a human being directing the operations of the mail client  130 , or alternatively may be another program using the mail client  130  to obtain information from the mail server  110 . 
     DYNAMIC DOWNLOADING OF HYPERTEXT ELECTRONIC MAIL MESSAGES 
     An electronic mail message  140  comprises a header  141 , comprising information about the electronic mail message  140 , and a body  142 , comprising information intended to be transmitted to the recipient of the electronic mail message  140 . 
     In a preferred embodiment, the header  141  comprises an address for a sender of the electronic mail message  140 , an address for at least one recipient of the message of the electronic mail message  140 , an element describing the subject of the electronic mail message  140 , and an element describing the size of the electronic mail message  140 . In a preferred embodiment, the header  141  is no more than about 250 bytes in size. 
     The display element  134  comprises a header window  151  within which information from the headers  141  is presented to the operator, thus showing the number and nature of electronic mail messages  140  which have been received and are available for download. 
     The body  142  comprises a plurality of pages  143  of information to be presented to the operator, such as web pages as described in the “Dynamic Preloading of Web Pages” co-pending application referred to herein. The pages  143  are logically coupled using links as described therein. Thus, each electronic mail message  140  comprises a linked collection of pages  143 , similar to a web site stored at a web page server for the World Wide Web. 
     In a preferred embodiment, each electronic mail message  140  may comprise links to actual web pages (i.e., web pages outside the collection of pages  143  comprising the electronic mail message  140  itself) stored at a web server or other server for accessing information. These actual web pages are accessed using the Hypertext Transfer Protocol (“HTTP”), or other protocols for transferring and presenting information, including protocols known as “FSP”, “FTP”, “Gopher”, and variants thereof, protocols for access to a command interface such as “Telnet”, “MUD”, “MUSH”, “MOO”, and variants thereof, other protocols for accessing, transmitting, or presenting information, and programs making use of such protocols., such as “Archie”, “Veronica”, “Jughead”, and the like. 
     In a preferred embodiment, each electronic mail message  140  may comprise links to application programs available at the mail client  130 , such as using Object Linking and Embedding (“OLE”), or a similar technique. For example, the electronic mail message  140  may comprise an embedded spreadsheet and an OLE link to a spreadsheet program for viewing or modifying the embedded spreadsheet. 
     The display element  134  comprises at least one page window  152 , each of which presents one of the pages  143  to the operator. Each page  143  is presented in like manner as web pages are presented in the “Dynamic Preloading of Web Pages” co-pending application referred to herein. For each page  143 , data included in the page  143 , including text, graphics, motion picture data, audio, or data in other formats, is presented to the operator within the page window  152 , along with any links, virtual links, included programs, security restrictions, or other features described in the “Dynamic Preloading of Web Pages” co-pending application referred to herein. 
     It is one aspect of the invention that electronic mail messages  140  are presented to the operator in like manner as web pages are presented in the “Dynamic Preloading of Web Pages” co-pending application referred to herein. In this aspect, the header window  151  is treated similarly to a web page in which each header  141  is treated similarly to a link to a first page  143  of its associated body  142 . 
     Thus, the operator may select one of the headers  141  so as to view its associated body  142 , to which the mail client  130  responds by downloading that body  142  and presenting a first page  143  of that body  142 . 
     Similarly to the preloading of web pages in the “Dynamic Preloading of Web Pages” co-pending application referred to herein, the mail client  130  downloads the associated body  142  for each electronic mail message  140  before its actual selection by the operator, so as to be able to present pages  143  from that body  142  by reference to the client storage  132  rather than having to download that body  142  and force the operator to wait during the download operation. 
     OPERATION OF THE MAIL CLIENT 
     The mail client  130  transmits a request to the mail server  110 , requesting transmission of the headers  141  for any electronic mail messages  140  which have been received and are available for downloading. In a preferred embodiment, the mail client  130  transmits such a request when it is first invoked, at periodic times, and when the operator so requests (such as by using a button or command character). 
     The mail client  130  receives headers  141  from the mail server  110  and presents those headers  141  in the header window  151  to the operator. 
     Responsive to the headers  141 , the mail client  130  selects individual electronic mail messages  140  and transmits requests to the mail server  110  to download those individual electronic mail messages  140 . As the electronic mail messages  140  are downloaded, they are stored in the client storage  132 . The mail client  130  selects a first electronic mail message  140  and presents that first electronic mail message  140  in the page window  152 . 
     The mail client  130  selects for downloading and downloads individual electronic mail messages  140  in like manner as web pages are selected for preloading and preloaded in the “Dynamic Preloading of Web Pages” co-pending application referred to herein. 
     Thus, in a preferred embodiment, the mail client  130  selects an individual electronic mail message  140  for downloading, and transmits a request to the mail server  110  to download that individual electronic mail message  140 . 
     When the operator selects a particular electronic mail message  140  for presentation, the mail client  130  determines if that particular electronic mail message  140  has been downloaded and is present in the client storage  132 . If so, the mail client  130  presents that particular electronic mail message  140  from the client storage  132 . If not, the mail client  130  transmits a request to the mail server  110  to download the newly selected electronic mail message  140 , downloads the newly selected electronic mail message  140 , and presents the newly selected electronic mail message  140  to the operator in the page window  152 . 
     The selection by the operator of a particular electronic mail message  140  for presentation takes priority over other download operations. The mail client  130  interrupts any other download operation to conduct the download operation requested by the operator. Thus, the mail client  130  may interrupt downloading and presentation of the headers  141  in the header window  151 , downloading of a different electronic mail message  140  selected for downloading by the mail client  130 , or even downloading of a different electronic mail message  140  selected for downloading by the operator (but for which the operator has apparently decided is lower priority). 
     As the mail client  130  downloads the electronic mail message  140 , it presents as much as possible of the electronic mail message  140  (such as a first page  143  of the electronic mail message  140 ) to the operator for dynamic review while the downloading operation is in progress. 
     When the downloading operation for the selected electronic mail message  140  is complete, the mail client  130  reverts to its behavior of downloading the headers  141  if they are not completely downloaded, and of selecting for downloading and downloading individual electronic mail messages  140  in like manner as web pages are selected for preloading and preloaded in the “Dynamic Preloading of Web Pages” co-pending application referred to herein. 
     Dynamic downloading of electronic mail messages  140  continues so long as there are electronic mail messages  140  available at the mail server  110  for which the operator is the intended destination. 
     PROGRESS INDICATOR 
     The mail client  130  presents the progress of downloading operations using a progress indicator  151 , in like manner as the page client presents the progress of preloading operations for web pages. 
     Thus, in a preferred embodiment, the progress indicator  151  uses one or more of the following preferred embodiments: 
     The progress indicator  151  may include a text element or a graphics element, having a first part  153  and a second part  154 , each having different colors, and altering the relative sizes of the first part  151  and the second part  152  as the download operation progresses. In this embodiment, the graphics element comprises a separate dot or small circle  155  associated with the header  141 ; or, the text element comprises the presentation of header  141  itself. 
     The progress indicator  151  may include a text element  156  or a graphics element shown outside the header window  151 . In this embodiment, the text element  156  comprises a phrase such as “75% complete” for a downloading operation which was in fact 75% complete; the graphics element may comprise a thermometer graph representing the progress of the downloading operation. 
     The progress indicator  151  may include a “thumbnail” picture  157  (i.e., a copy of a page  143  of the electronic mail message  140  presented in miniature), presented at a location outside the header window  151 . In this embodiment, the progress indicator  151  comprises a first part  153  and a second part  154 , in which the first part  153  comprises a segment of the thumbnail picture  157  which presents information from a page  143  of the electronic mail message  140  as that electronic mail message  140  downloaded, and the second part  154  comprises a background color or other indicator that further data is yet to be downloaded. Thus the thumbnail picture  157  will fill the location for its presentation as the downloading operation progresses. 
     ORDERING ELECTRONIC MAIL MESSAGES FOR DYNAMIC DOWNLOADING 
     In a preferred embodiment, the mail client  130  dynamically orders the electronic mail messages  140  for downloading, and selects those electronic mail messages  140  for downloading which the mail client  130  dynamically considers should be downloaded first. 
     Since the operator is likely to ultimately desire to review all the electronic mail messages  140  which are received, the mail client  130  will, unless directed otherwise by the operator, download all the electronic mail messages  140  whose headers  141  are presented by the mail server  110 . 
     Similarly to the “Dynamic Preloading of Web Pages” co-pending application referred to herein, the mail client  130  makes its selection responsive to one or more of the following factors: (1) the operator may explicitly select a particular electronic mail message  140  for downloading (e.g., while the operator reviews a different electronic mail message  140 ); (2) the operator may explicitly select a set of downloading preferences and priorities. 
     To explicitly select a particular electronic mail message  140  for downloading, the operator selects the electronic mail message  140  for downloading using the input element  133 , such as by pointing to the associated header  141  or to its preloading indicator  151  and selecting the electronic mail message  140  for downloading. 
     If the operator selects a particular electronic mail message  140  for downloading, the selected electronic mail message  140  takes priority and is downloaded before other electronic mail messages  140  which might be downloaded for other reasons. 
     When the operator explicitly selects a set of downloading preferences and priorities, the mail client  130  receives the downloading preferences and their relative priorities from the operator, and stores the downloading preferences and their relative priorities in the client storage  132 . When the mail client  130  receives the headers  141 , it reviews the downloading preferences and their relative priorities, and downloads those electronic mail messages  140  which are indicated by the downloading preferences in the order of their relative priorities. 
     The downloading preferences select among those links  150  to electronic mail messages  140  responsive to one or more of the following factors: 
     the sender of the electronic mail message  140 ; 
     whether this recipient of the electronic mail message  140  is the only recipient or one of several recipients; 
     a priority value set by the sender for the electronic mail message  140 , such as “urgent” or “bulk mail”; 
     keywords in the header  141  or the body  142  of the electronic mail message  140 ; or 
     the size of the electronic mail message  140 . 
     SENDING ELECTRONIC MAIL MESSAGES 
     In a preferred embodiment, the mail client  130  receives information from the operator to compose electronic mail messages  140  (either new electronic mail messages  140  or in reply to electronic mail messages  140  which have been received). The mail client  130  presents outgoing electronic mail messages  140  which are being composed in an outgoing window  153 . 
     When the operator indicates that the outgoing electronic mail messages  140  are complete, the mail client  130  records them in the client storage  132  and uploads them at the next time when there is no downloading operation in progress. However, the operator may direct the mail client  130  (e.g., using a command invoked using a button or a control character) to interrupt any downloading operation which is in progress and to send one or more of the outgoing electronic mail messages  140  immediately. 
     Alternative Embodiments 
     Although preferred embodiments are disclosed herein, many variations are possible which remain within the concept, scope, and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application.