Abstract:
An email proxy server system gives the user access to all of their email accounts through a unified port. The proxy server maintains a mail registration database associating the user&#39;s ID with multiple email accounts, which may be hosted on different Internet providers and otherwise. The email messages stored on the email hosts may be in POP3 format, which configuration the proxy server imitates to give the user an impression of transparent access to all of their email accounts. Because the ability to access individual mail boxes is unbound from particular internet addresses, one user may maintain any number of email mail boxes at different hosting servers, and change those addresses, without having to reprogram client, server, and other software. Moreover, the presentation of the integrated interface of the invention permits system administrators to attach service modules, such as billing and other packages directly to the proxy server to serve each of the different email accounts, without having to tailor those individual services to individual hosts hardware.

Description:
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/132,098, filed Apr. 30, 1999. 

   FIELD OF THE INVENTION 
   The invention relates to the field of communications, and more particularly the integrated management of multiple email accounts. 
   BACKGROUND OF THE INVENTION 
   The advent of the Internet has increased the demand for email and other electronic messaging services. Most Internet service providers (ISPs) offer email accounts automatically when a new user is registered. In terms of Internet email transport, the overall client/server protocol employed for transmitting email messages is the Simple Mail Transfer Protocol (SMTP). The host mail server run by the typical ISP includes an SMTP server, which handles email by managing queues and reconciling addresses. Most ISPs offer consumer Internet accounts based on dial-up (PPP) protocols. Under this protocol the consumer client, operating a personal computer or other device, uploads mail to the host email server using SMTP and downloads mail using the Post Office Protocol, presently version 3 (POP3). The typical architecture is illustrated in  FIG. 1 . POP3 is a low-overhead protocol for general download service, offering the ability to perform basic operations such as listing and deleting email messages. 
   However, deploying POP3 for email access entails disadvantages. One is that the client&#39;s personal computer must be programmed to know the precise address of the root email mailbox, by identifying the IP address of the host mail server. If the account holder&#39;s mailbox is moved to a different host mail server at a different IP address, the software on the client&#39;s personal computer must be reprogrammed to reflect the new destination. As a result, ISPs are reluctant to move account holder mailboxes, and can only do so with great attention. This limits the flexibility of ISPs in deploying new mail hosting technologies, including to change or upgrade mail servers. 
   Another disadvantage of the POP3 architecture is that if an account holder chooses to change ISPs entirely, there is in general no mechanism to transfer the account holder&#39;s email mailbox to the new service provider, intact. There is, moreover, no provision for the coexistence of two mailboxes with the same account name but different mail server hosts. Thus, a consumer who has changed ISPs must periodically check both the old email mailbox and the new mailbox until the transition is complete. Similarly, when an account holder maintains both a business email address and a personal email address, they must access each of those mailboxes separately. 
   Moreover, on the server side, ISPs need to maintain their host mail servers with modules to register and process billing information, account statistics and other value-added services. There are no industry standards for those mail server services, and they vary from one ISP to the next. Consequently, individual ISPs are effectively locked into a single vendor&#39;s package to maintain attendant services at the level of the mail server, or be forced to write conversion software when a new service package is introduced, so as not to disrupt the addressing scheme for their customers. Other problems exist. 
   SUMMARY OF THE INVENTION 
   The invention overcoming these and other problems in the art relates to an integrated message management system and method, including a proxy server, which mediates the delivery of messages between a client workstation and multiple POP3 email servers. The proxy server communicates with the client workstation using the POP3 protocol, and maintains an associated mail registration database. The mail registration database contains entries for all of the user&#39;s email accounts, their IP addresses and associated ISP entities. 
   When the user wants to access their mail, the proxy server distributes mail update requests to one or more of the POP servers belonging to the user. Localizing and integrating all of the user&#39;s account addressing and other information within the dedicated proxy server relieves the user and the network service provider from needing to reprogram clients and servers every time a new email account is shifted, added or deleted. Among other advantages, this permits relatively painless and transparent migration and the coexistence of multiple mailboxes. The invention affords greater latitude in the movement of an email mailbox amongst mailbox servers of different types, as well. 
   From the server point of view, the invention also allows the ISP to both deploy a common interface to the client workstation as a front-end manager, as well as permit a unified interface for server-side administrative packages. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described with respect to the accompanying drawings, in which like elements are indicated by like numbers. 
       FIG. 1  illustrates an email architecture according to conventional delivery protocols. 
       FIG. 2  illustrates a network architecture for integrated message management according to the invention. 
       FIG. 3  illustrates aspects of a proxy server used in the invention. 
       FIGS. 4 and 5  illustrate a flow chart of message processing according to the invention. 
       FIG. 6  illustrates an email management process presented to a user according to the invention. 
       FIG. 7  illustrates a directory structure of a mail registration database according to the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The invention will be described with respect to an overall messaging architecture illustrated in  FIG. 2 . As illustrated in  FIG. 2 , in the network environment of the invention a client workstation  102  communicates via communications link  104  with a proxy server  106 . Client workstation  102  may be, for instance, a personal computer running the Windows™ 95, 98 or NT™, Unix, Linux or other operating systems, and communications link  104  may be a dial-up connection, ISDN, DSL, Ethernet, cable modem, T1 or T3, or other wired or wireless digital or analog communications connection. Proxy server  106  may be, for instance, a workstation running the Windows™, NT™, Unix, Linux or other operating systems. 
   In the illustrative embodiment, the configured protocol between client workstation  102  and proxy server  106  is the Point to Point (PPP) standard, familiar to persons skilled in the art. Proxy server  106  is connected over connection  112  to a mail registration database  108 , in which user ID, account number, ISP, Internet addressing and other information is stored. Connection  112  may be configured according to the LDAP or other protocols. 
   Proxy server  106  is connected via communications link  110  to a plurality of distributed email servers,  114   a ,  114   b  . . .  114   n  (n arbitrary), which host individual email or other messaging accounts. Communications link  110  may be, for instance, a T1 or T3, frame relay, DSL, cable modem, fiber optic, or other wired or wireless, analog or digital, backbone or other connection, including linkage to or through the Internet. Each of the email servers  114   a ,  114   b  . . .  114   n  is attached to a respective local email database  118   a ,  118   b  . . .  118   n  which hosts incoming and outgoing email messages according to the SMTP, MIME or other network protocols. 
   Each mail server  114   a ,  114   b  . . .  114   n  is connected to its respective email database via corresponding connection  116   a ,  116   b  . . .  116   n , each of which may be configured according to the Standard Query Language (SQL) Net protocol or others. In general, the proxy server  106  communicates with remote email servers  114   a ,  114   b  . . .  114   n  using the POP3 scheme, and also communicates with the client workstation  102  using POP3 to identify, retrieve and transmit electronic mail messages. 
   As illustrated in  FIG. 3 , proxy server  106  may contain a processing unit  120 , memory  122  such as electronic RAM, input/output interface  126  and local storage  128  such as a hard drive, connected over an electronic bus  130 , as will be appreciated by persons skilled in the art. 
   Client applications which service an electronic mailbox using the POP3 standard generally proceed through several predefined states during the course of connecting to an email server. Those states include: 
   TABLE 1 
   
       
       
         
           1. Authorization State: The user has not identified themselves to the email server. 
           2. Transaction State: The user has received authorization to access a mailbox on the email server. The user may issue commands to the email server to list and retrieve messages, and mark selected messages for deletion. 
           3. Update State: After a user has completed desired retrievals and deletions, the user may issue a quit command, which moves the session to the update state. During this state, the email server deletes any messages that were marked for deletion and terminates the connection to the client. 
         
       
     
  
   With conventional access packages, for each mailbox that a user wishes to enter, they must go through each of these successive states in serial fashion. While doing so, the user must keep track of the identity and address of each of the POP3 email servers to which they need to connect. In the invention, in contrast, and as illustrated in  FIG. 6 , a user at client workstation  102  connects to and is serviced by proxy server  106  by presentation of interface module  132  on the client workstation  102 . The interface module  132  presents an integrated view into all of the users&#39; available email accounts, regardless of service provider or location. The user may, in general, view a list of all pending email messages, and mark individual messages for download or deletion from interface module  132 , without needing to separately access or address each of mail servers  114   a ,  114   b  . . .  114   n . Interface module  132  is in one regard illustrated in  FIG. 6 . 
   An illustrative sequence of message processing is shown in  FIGS. 4 and 5 . In step  202 , processing begins. In step  204 , client workstation  102  connects to proxy server  106 . In step  206 , proxy server  106  transmits a greeting with a message ID to the client workstation  102 . In step  208 , client workstation  102  transmits to proxy server  106  an APOP name digest to the proxy server  106 , indicating an authorized identity of the user at client workstation  102 . In step  210 , proxy server  106  performs a look-up of the user&#39;s name digest against mail registration database  108 . 
   In step  212 , proxy server  106  validates the user&#39;s identity, and in step  214  transmits a message to client workstation  102  indicating acceptance of the user&#39;s access request over communications link  104 . In step  216 , proxy server  106  initiates transactions with one or more of mail servers  114   a ,  114   b  . . .  114   n  by establishing a connection to those servers via communications link  110 . In step  218 , the email servers  114   a ,  114   b  . . .  114   n  respond with a handshake greeting to proxy server  106 . In step  220  proxy server  106  transmits to each mail server  114   a ,  114   b  . . .  114   n  user account name information particular to the user&#39;s individual account with each service provider, by looking up ID, password and associated information in mail registration database  108 . In step  222 , email servers  114   a ,  114   b  . . .  114   n  respond with an authorization okay indication to proxy server  106 . 
   After the authorization transactions between proxy server  106  and the distributed email servers  114   a ,  114   b  . . .  114   n , the proxy server  106  transmits to each of the email servers  114   a ,  114   b  . . .  114   n  a list command to initiate the generation and transmission of a list of pending email messages from each of the individual servers. In step  226 , the email servers  114   a ,  114   b  . . .  114   n  respond and transmit to proxy server  106  a message list of pending email messages using the POP3 protocol. 
   In step  228 , the proxy server  106  consolidates the message list received from each of the email servers  114   a ,  114   b  . . .  114   n  for presentation to the user in consolidated message list  134 . In step  230 , the user at client workstation  102  transmits a list request to proxy server  106 . In step  232 , proxy server  106  transmits to the user a list of all pending email messages retrieved from all of the user&#39;s accounts, which is presented via interface module  132 . In step  234 , the user manipulates the interface module  132  using an input device such as a mouse or keyboard to indicate which messages within the consolidated message list  134  are desired to be retrieved. 
   In step  236 , the proxy server  106  receives the retrieve command from the required workstation  102  and maps the selected message numbers to associated email accounts with corresponding email servers among email servers  114   a ,  114   b  . . .  114   n . In step  238 , proxy server  106  transmits to the selected email servers a retrieve command to retrieve the user&#39;s selected email messages from the local message storage database  118   a ,  118   b  . . .  118   n  for those servers. In step  240 , the selected email servers transmit the indicated messages to the proxy server  106 . In step  242 , the proxy server  106  maps the return message to the listed consolidated message list number on interface module  132 . In step  244 , proxy server  106  transmits the selected messages to client workstation  102  using the POP3 protocol. 
   In step  246 , the user at client workstation  102  transmits a delete command to delete selected messages of those presented within the consolidated message list  134 , and in step  248  proxy server  106  marks the messages selected for deletion by the user in the consolidated message list  134 . In step  250 , the proxy server  106  transmits to client workstation  102  an OK signal indicating that deletion has been prepared, after which in step  252  client workstation  102  transmits to proxy server  106  a quit command indicating the user&#39;s desire to terminate the message retrieval session. 
   Upon receipt of the quit command, the proxy server  106  transmits in step  254  a delete command to individual email servers  114   a ,  114   b  . . .  114   n  hosting the email messages selected for deletion. In step  256 , the email servers  114   a ,  114   b  . . .  114   n  receiving the delete command delete the corresponding email messages, and transmit back to proxy server  106  a delete completion signal indicating that the pending messages have been deleted. In step  258 , proxy server  106  transmits a quit command to each of the email servers  114   a ,  114   b  . . .  114   n . After receipt in step  260  each of the email servers  114   a ,  114   b  . . .  114   n  respond with a quit acknowledge flag to the proxy server  106  and terminate the POP3 connection over communications link  110 . In step  262 , proxy server  106  transmits a session termination message to client workstation  102 , causing interface module  132  to indicate the exiting from the message access session. In step  264 , processing ends. 
   Thus, after the proxy server  106  validates a user using their user ID and password against the mail registration database  108 , the proxy server  106  obtains the locations and IP addresses of the user&#39;s email mailboxes. The mail registration database  108  is illustrated in more detail in  FIG. 7 . As shown in that figure, the mail registration database contains global registration object  140  containing one or more profile association records  142 , which relate a user ID to password, mailbox address and related fields. The proxy server  106  establishes connections to each such mailbox, retrieves a list of pending email messages and presents a consolidated message list  134  to the user on client workstation  102  via interface module  132 . 
   The proxy server  106  then processes any further commands from the client workstation  102 , including NOOP, LIST, STAT, DELE, and RSET commands without necessarily interacting with the backend email servers. It is only necessary for the proxy server  106  to interact with the email servers  114   a ,  114   b  . . .  114   n  when the client workstation issues a command to retrieve a message or to quit the messaging session. 
   Because the proxy server  106  imitates a POP3 mail server from the point of view of the client workstation  102 , proxy server  106  can parse the commands and semantics of all the interactions which occur with the client workstation  102  and present an integrated message port. Proxy server  106  may use this ability to intercept commands issued by client workstation  102  to provide further value added services using administrative module  136 , associated with and running on proxy server  106 . 
   Administrative module  136  may perform such activities as recording billing information, archives, links, cookie and other information, and logging connection statistics and other information, all on behalf of a single user entering the messaging system of the invention via proxy-server  106 . Thus, in the practice of the invention an extensible set of service processes may be incorporated in administrative module  136  to make the maintenance, billing and other operational aspects of the overall communication system easier to upgrade, maintain and more reliable for service providers. 
   The foregoing description of the invention is illustrative, and variations in configuration and implementation will occur to persons skilled in the art. For instance, while the invention has been described with respect to the retrieval of text or email messages, other kinds of message information, such as digitized voice, facsimile, alpha-numeric pages and other information may be accessed and retrieved by the invention. 
   Similarly, while the invention has been described with respect to a single proxy server  106  which collects and distributes email information, the invention may be carried out using an architecture having more than one proxy server giving multiple access points and connection accounts to the user. Or, the functionality described as being executed on a dedicated proxy server  106  may be distributed to one or other hardware resources, including client workstation  102 , routers, gateways and other devices. The scope of the invention is accordingly intended only to be limited by the following claims.