Patent Publication Number: US-7222158-B2

Title: Third party provided transactional white-listing for filtering electronic communications

Description:
TECHNICAL FIELD 
     The following description generally relates to electronic communications and, more particularly, to the use of white-listing to permit electronic communications between entities. 
     BACKGROUND 
     As the use of electronic communications, such as e-mail communications, has increased, so has the occurrence of unsolicited bulk communications, also called spam. While spam often is commercial in nature, it also includes non-commercial bulk communications, such as political or non-profit communications sent to large numbers of electronic communication users. To control and prevent spam, communication users employ spam filter systems. Two types of spam filter systems are black-listing systems and white-listing systems. A black-listing system maintains a list, called a black-list, of user names, e-mail addresses, domain names, or other identifying information for communication users such as these who are known or likely to send spam. Black-listing systems block communications from any user who appears on the black-list. Conversely, a white-listing system works by maintaining a list, called a white-list, of user names, e-mail addresses, domain names, or other identifying information for approved communication users. White-listing systems accept communications from any user who appears on the white-list. 
     SUMMARY 
     In one general aspect, transactional white-listing to facilitate electronic communications includes receiving an out-of-band communication from a third-party service provider in response to an action by an intended communications recipient. The out-of-band communication contains information identifying an expected communications sender and an intended communications recipient. The expected communications sender sends communications to the intended communications recipient over a communication channel other than the channel through which the out-of-band communication was received. If the identifying information for the expected communications sender does not appear in a white-list associated with the intended communications recipient, it is added to the white-list associated with the intended communications recipient. 
     Implementations may include one or more of the following features. For example, upon expiration of a specified time period, the identifying information for the expected communications sender may be deleted from the white-list associated with the intended communications recipient. If the identifying information for the intended communications recipient does not appear in a white-list associated with the expected communications sender, such identifying information may be added to the white-list associated with the expected communications sender. The identifying information may be an e-mail address, an IM screen name, an IP address, a MAC address, or a domain name. 
     Further, upon receipt of a communication from the expected communications sender, the communication may be sent to the intended communications recipient. The received communication may be an e-mail, an instant message, a telephone call, or a message posted to an online message board. After sending the communication to the intended communications recipient, the identifying information for the expected communications sender may be deleted from the white-list associated with the intended communications recipient. The intended communications recipient also may be notified that the expected communications sender is scheduled to be removed from the white-list. In such a case, the intended communications recipient may be asked whether the expected communications sender should be kept in the white-list. 
     In another general aspect, transactional white-listing includes receiving a communication from a third-party service provider over an out-of-band communication channel. The out-of-band communication, which identifies an expected e-mail sender and an intended e-mail recipient, is received by a communications service provider associated with the intended e-mail recipient. The transactional white-listing further includes determining whether the communication service provider has a global white-list for e-mail filtering. If the communications service provider has a global white-list, information identifying the expected e-mail sender and a transactional identifier is automatically added to the global white-list. Similarly, the transactional white-listing also determines whether the intended e-mail recipient has a personal white-list for e-mail filtering. If the intended e-mail recipient has a personal white-list, the information identifying the expected e-mail sender and the transactional identifier is automatically added to the personal white list of the intended e-mail recipient. 
     In some implementations, automatically adding information identifying the expected e-mail sender and a transactional identifier to the global white-list includes adding a type indicator, the type indicator permitting special handling of in-band communications. Implementations may involve determining whether the communications service provider has a global black-list for e-mail filtering and whether the expected e-mail sender is blocked by the global black-list from sending e-mail to the intended recipient. If the expected e-mail sender is blocked by a global black-list, the global black-list automatically is modified to permit the expected e-mail sender to send e-mail to the intended e-mail recipient. It further is determined whether the intended e-mail recipient has a personal black-list for e-mail filtering and whether the expected e-mail sender is blocked by the personal black-list from sending e-mail to the intended recipient. If the expected e-mail sender is blocked by the personal black-list, the personal black-list automatically is modified to permit the expected e-mail sender to send e-mail to the intended e-mail recipient. 
     In other general aspects, automatically adding an e-mail address of a e-mail sender to a list of approved e-mail sender addresses associated with an intended e-mail recipient, where the e-mail address of the e-mail sender is provided by a third party service provider sending an out-of-band communication to a communications service provider associated with the intended recipient and where the out-of-band communication is provided in response to an action by the intended e-mail recipient, includes receiving an out-of-band communication from a third-party service provider. The out-of-band communication specifies an e-mail address of an e-mail sender and an e-mail address of an intended e-mail recipient. The e-mail address of the e-mail sender is added to a list of approved e-mail sender addresses associated with the intended e-mail recipient, whereby the intended e-mail recipient can receive e-mail from the e-mail sender. The e-mail address of the e-mail sender is deleted from the list of approved e-mail sender addresses associated with the intended e-mail recipient upon completion of a specified end trigger. 
     Some implementations involve adding a transactional identifier, time stamp, or expiration date to the list. Further, the out-of-band communication may be received over a virtual private network or using a remote procedure call. 
     The specified end trigger may be an out-of-band communication from the third party service provider indicating that the e-mail address for the e-mail sender should be removed from the list of approved e-mail sender addresses associated with the intended e-mail recipient. The specified end trigger may be expiration of an expiration date, expiration of a specified time duration, receipt of an e-mail by the intended e-mail recipient, or receipt of a threshold number of e-mails from the e-mail sender. It may be initiated by the third-party service provider or by an e-mail service provider. 
     In another general aspect, automatically configuring a white-list communications filter associated with a communications user includes a communications gateway configured to receive out-of-band communications from one or more authorized third-party service providers. It further includes a communications filter system that maintains a white-list communications filter identifying trusted communication sources, and a means for automatically configuring the white-list communications filter based on the out-of-band communications received by the communications gateway. One additional feature in some implementations includes a means for permitting manipulation of the communications filter system by a user. 
     In yet another general aspect, facilitating electronic communications involves receiving an out-of-band communication identifying a first communications user that is expected to send communications to an identified second communications user. Based on the received out-of-band communication, a white-list is configured to temporarily permit communications from the first communications user to be received by the second communications user. A black-list is configured to temporarily prevent communications from the first communications user from being blocked by the black-list. 
     Other general aspects of transactional communications filtering includes receiving an out-of-band communication identifying an expected communications sender and an intended communications recipient. The out-of-band communication indicates that the expected communications sender should be permitted to send communications to the intended communications recipient for a set transactional period. If communications sent to the intended communications recipient is filtered through a global white-list or a personal white-list, transactional information identifying the expected communications sender is added to the global white-list and the personal white-list. If such communications also are filtered through a global black-list that would prevent receipt of communications from the expected communications sender, a transactional exception for the expected communications sender is automatically created in the global black-list, whereby the created exception prevents the global black-list from blocking communications from the expected communications sender. Likewise, if communications sent to the intended communications recipient is filtered through a personal black-list that would prevent receipt of communications from the expected communications sender, a transactional exception for the expected communications sender is created in the personal black-list, whereby the created exception prevents the personal black-list from blocking communications from the expected communications sender. 
     The out-of-band communication, in some implementations, includes a transactional identifier. One implementation further includes, upon occurrence of an end trigger, removing the transactional information from the global and personal white-lists and removing the transactional exception from the global and personal black-lists. An option may be presented to allow the intended communications recipient to make the transactional information in the global and personal white-lists and the transactional exception in the global and personal black-list permanent, whereby the expected communications sender is permitted to send communications to the intended recipient after the conclusion of a set transactional period. 
     The personal white-list may be maintained on a server associated with a communications service provider that provides communication services to the intended communications recipient, or it may be maintained on a local device used by the intended communications recipient. The local device may be a personal computer, a personal digital assistant, or a cellular phone. 
     Another general aspect of facilitating electronic communications between two entities includes receiving an out-of-band communication from an authorized third-party source, wherein the out-of-band communication contains information identifying an expected communications sender and an intended communications recipient. Based on the received out-of-band communication, the identifying information for the expected communications sender is added to a list of approved communications senders associated with the intended communications recipient. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       Throughout the drawings, reference numbers are re-used to indicate correspondence between referenced elements. Additionally, the first digit of each three-digit reference number and the first two digits of each four-digit reference number generally indicate the figure in which the element first appears. 
         FIG. 1  is a high-level block diagram of a transactional white-listing system. 
         FIGS. 2 ,  3 , and  4  are block diagrams of a transactional white-listing system using electronic mail. 
         FIGS. 5 ,  6 ,  7 , and  8  are example user interfaces that may employ a transactional white-listing system. 
         FIG. 9A  is a flow chart illustrating a method employed by a transactional white-listing system to add entries to white-lists. 
         FIG. 9B  is a flow chart illustrating a method employed by a transactional white-listing system to add entries to white-lists. 
         FIGS. 10A and 10B  comprise an operational flow diagram illustrating an example operation of the methods and systems described in  FIGS. 1–4  and  9 . 
         FIG. 11  is a flow chart illustrating a method employed by a transactional white-listing system to remove entries previously added to the white-lists by the transactional white-listing system. 
         FIG. 12  is an example user interface that may be employed by a transactional white-listing system. 
     
    
    
     DETAILED DESCRIPTION 
     It is useful to provide a mechanism to allow, at least temporarily, communications to occur without blocking between a first entity and a second entity with whom communications with the first entity are likely/anticipated and desirable, generally through use of a white-list having transactional entries. For example, to allow communications between a communications user and an intended recipient, the user may be added to a white-list for or until a specified transaction or duration. The addition of a user to a white-list may occur in response to a start trigger indicating that desirable or non-spam communications likely will be received from the user during some temporary period or on/before some triggering event. To ensure open communications, the user may be added to global and personal white-lists associated with the intended recipient. Thereafter, the user is removed from the global and personal white-lists upon occurrence of an end trigger, which may include an event (such as receipt of the communication) or expiration of a specified period of time or time threshold. Thus, the disclosed systems and methods permit the transactional white-listing of users for a limited time necessary to ensure the intended recipient receives the anticipated communications. 
     The transactional white-listing systems and methods guard against the anticipated communications being accidentally marked or blocked as spam by other communications filters. They also prevent cluttering white-lists with information about users with whom the intended recipient interacts in a finite number of transactions or for only a time-limited transaction. In many implementations, this transactional white-listing is performed without the need for input from the intended recipient, who may or may not be aware of the transactional white-listing done on his behalf. Throughout the description references to automatic actions may correspond to actions taken without individual user intervention or actions taken without required user action. 
     In one implementation, in response to the start trigger, a third-party service provider notifies a communications service provider (CSP) associated with the intended recipient of the need to white-list an expected sending user. That notification may be provided using an out-of-band or back channel connection between the third-party service provider and the CSP. The out-of-band communication data thus is provided independent of the future communication. The CSP adds information identifying the sending user to any existing global white-lists with a transactional identifier to allow the CSP to later remove the sending user upon occurrence of an end trigger. The CSP then adds the identifying information for the sending user and the transactional identifier to the personal white-lists of the intended recipient. Generally, this process is transparent to both the sending user and the intended recipient. The process also may check any global and personal black-lists to determine whether the sending user appears in any black-list. If the user appears in any such black-list, the process may create an exception in the black-list or inactivate the entry in the black-list(s) to ensure that communications from the sending user are received by the intended recipient. 
     Thereafter, upon satisfaction of the temporary condition, identifying information for the temporarily white-listed sender may be removed from any global or personal white-lists associated with the intended recipient. Specifically, upon occurrence of an end trigger, the CSP removes identifying information for the white-listed sender from the global and personal white-lists associated with the intended recipient. Furthermore, if previously excepted, removed, or inactivated from a black-list, identifying information for the sending user also is reentered or reactivated in the black-list. The end trigger may be, for example, another communication from the third-party service provider, the expiration of a specified duration, or the occurrence of a specified transaction or event. In one implementation, the specified duration may be potentially infinite, or may be set by another event or condition. For example, the duration may be specified to be “as long as the intended recipient maintains an account with the third-party service provider.” Examples of the third-party service providers include any third-party provider of online or World Wide Web (Web) based services, such as ebay.com or amazon.com. The CSPs include providers of communication services, such as America Online (AOL), Yahoo, or Microsoft Networks (MSN) Hotmail. 
     Examples of the disclosed systems and methods to white-list expected sending users exists in many differing contexts. One such context is an online auction website, such as ebay.com, where a potential buyer of an item being sold wishes to ask the seller a question. Because some online auctions do not disclose the contact information of the seller, it may be difficult for conventional systems to guarantee that the communications system of an inquiring potential buyer will not block responsive communications sent by the seller, even though the potential buyer clearly desires to receive such communications. By the contrast, however, the disclosed white-listing systems and methods provide a way to ensure that the potential buyer can receive communications from the seller even though the potential buyer does not know the contact information of the seller and may not know the identity of the seller. In this context, through out-of-band communications between ebay.com and the communications system of the inquiring potential buyer, the seller may be transactionally white-listed for the potential buyer when the potential buyer indicates a desire to ask the seller a question. 
     Another example is the use of the systems and methods in an information request context. In that context, a requestor who requests information from an online source, such as by completing a website information request form, can receive responsive communications from entities associated with the online source. One specific instance involves submission by a requester of a request for information about a locale that the requestor anticipates moving to or visiting during a upcoming vacation. For example, a user contemplating a move to a new area of the United States may visit a website for that area, such as a city or chamber of commerce website, and fill out a form to receive more information from local realtors, schools, or utility companies. Such a request for information may prompt the white-listing of more than one of those or other entities to enable responses to the requested information. It may involve white-listing local realty companies as well as local schools and utility companies. Such information requests also may be made about consumer products or health related problems by completing request forms from appropriate websites. Using the disclosed systems and methods, one or more entities may be transactionally white-listed to ensure the appropriate response(s) to such information requests. 
     Yet another example involves online purchases. For example, a purchaser of an airplane ticket may want to receive communications from the airline about the ticket up through the return date of the ticket. This would allow the purchaser to receive communications informing of any cancellations or scheduling problems with the purchaser&#39;s flights. In this instance, a third-party service provider, such as travelocity.com or expedia.com, may send out-of-band communications to white-list the domain of the particular airline for which the purchaser bought the ticket (e.g., Delta, Southwest, American Airlines). Likewise, an online purchaser of a pair of shoes may wish to receive communications related to their purchase, such as a confirmation receipt or shipping information. In both situations, the disclosed systems and methods may be used to transactionally white-list the appropriate entities for a specified duration, such as until the date of the return airplane flight or until the shipment is delivered. 
     These and other features will be described now with reference to the drawings identified above. The drawings and their associated descriptions are provided to illustrate various implementation-specific details, and not to limit the scope of the invention set forth in the appended claims. For the sake of explanation, some drawings may illustrate concepts as embodying separate components. As understood by one of ordinary skill, however, the substitution of a single component for the shown components does not necessarily render the substitution different from the shown implementation. Additionally, for simplicity, the drawings may show some components as single entities when, as understood by one of ordinary skill, such components may be implemented in multiple instances of the components. For example, a server or database may be illustrated as a single entity though implemented across multiple servers or databases. Further, although the drawings do not show the presence of a network or web, it is understood that any of the shown connections between the illustrated components and systems may occur over a network, the Internet, or the Web. 
     I. System Overview 
       FIG. 1  is a high-level block diagram of one implementation of a transactional white-listing system  100  incorporating CSPA communications system  102 , CSPB communications system  104 , and third-party service provider system  106 . In the shown implementation, CSPA communications system  102  includes CSPA communications server system  108  and communications application system  110 . CSPA communications server system  108  is configured to facilitate electronic communications between a subscribing CSPA user and other entities and persons. These communications often occur over the Internet or the Web. The communications may involve e-mail, instant messaging (IM), chat or message boards, voice mail, caller identifier (ID), or any facilitated peer-to-peer communications. For example, in an instant messaging environment, CSPA communications server system  108  is configured to facilitate instant messaging between users. In a voice mail context, CSPA communications server system  108  is configured to provide voice mail services. 
     Communications application system  110  is identifiable to CSPA communications server system  108 , and is configured to send and receive electronic communications using the services provided by CSPA communications server system  108 . Communication application system  110  is shown separately from CSPA communications server system  108  solely for explanation purposes. It may form an actual part of the CSPA communications server system  108 , as with some web-based CSPs, or it may be a separate client-side component identifiable to CSPA communications server system  108  over a network or the Web. In the above example of instant messaging, communication application system  110  is an instant messaging application running on central servers or client devices. 
     A communications channel  112 , called an out-of-band or back channel, connects CSPA communications server system  108  with one or more third-party service provider systems  106  (for simplicity, only one such system is illustrated). This out-of-band channel  112  is configured to securely carry information and data between CSPA communications server system  108  and third-party service provider system  106 . Out-of-band communications channels include non-anonymous channels, such as, for example, a virtual private network (VPN), a remote procedure call (RPC) channel, or other such web services or hypertext transfer protocol (HTTP) channels. Third-party service provider system  106  may be systems for any third-party service provider, such as an online retail provider, auction provider, or help or information provider. Both third-party service provider system  106  and CSPA communications server system  108  can send and receive communications over out-of-band channel  112 . As shown in  FIG. 1 , third-party service provider system  106  also is configured to communicate with CSPB communications system  104  via CSPB communications server system  114  over channel  116 . Channel  116  may be in-band channel. The in-band channel carries communications between users in contrast to the out-of-band channel, which connects third-party service provider system  106  to CSPA communications server system  108 . Similar to CSPA communications server system  108 , CSPB communications server system  114  is configured to facilitate communications over the Web between a subscribing CSPB user and other entities and persons. Communications application system  118 , which is identifiable to CSPB communications server system  114 , is configured to send and receive electronic communications using the services provided by CSPB communications server system  114 . It may send such communications to communication application system  110  via CSPA communications server system  108  over in-band channel  120 . Although communications application system  118  is shown separate from CSPB communications server system  114 , it also may be an actual component in CSPB communications server system  114 . Additionally, as indicated above, each of the connections and channels between the illustrated components and systems may occur over a network, the Internet, or the Web. 
       FIG. 2  shows an example of a white-listing system  200  implemented in an e-mail communications environment. Such an e-mail communications environment might be, for example, an online auction website like ebay.com (see example user interface in  FIG. 5 ). System  200  includes CSPA e-mail system  202 , CSPB e-mail system  204 , and third-party service provider system  206 . CSPA e-mail system  202  includes CSPA e-mail server system  208  and e-mail application system  210 . CSPA e-mail server system  208  is configured to facilitate e-mail between CSPA e-mail users, such as user A1  222 , and other e-mail users on a network or the Web. E-mail user A1  222  sends and receives e-mails over the network or the Web using e-mail application system  210  (which is uniquely configured for user A1  222 ) and the various e-mail related services, such as e-mail filtering, of CSPA e-mail server system  208 . In the depicted implementation, either or both of CSPA e-mail server system  208  and e-mail application system  210  filter received e-mails through white-lists to control and eliminate spam. CSPA e-mail server system  208  has global white-list  224  that filters the aggregated collections of e-mails that are received or directed to individual or multiple of the e-mail users associated with or using server system  208 . Individual subscribing e-mail users also may further filter e-mails using a personal white-list specific to their identity. E-mail to user A1  222 , for example, is filtered through personal white-list  226  before actually being displayed to user A1  222 . 
     For simplicity, only one subscribing e-mail user, user A1  222 , is shown; however, it is understood that CSPA e-mail server system  208  provides e-mail services for many different subscribing e-mail users. Each of these e-mail users, like user A1  222 , may use a personal white-list, such as white-list  226 , to further filter received e-mails sent directly to that e-mail user. Global white-list  224  and personal white-list  226  contain information and data identifying e-mail users that are approved e-mail senders. E-mail from these approved senders, which may be subscribers of CSPB or of any other CSP, is passed through to its intended recipient without being blocked by other spam filtering systems. For example, user A1  222  receives all e-mail from e-mail users that are listed in both global white-list  224  and personal white-list  226 . Personal white-ist  226  may be maintained on a non-local server system or on a local device used by the user. Examples of local devices include personal digital assistants, personal computer, cellular phones, connected consumer electronics devices (e.g., video conferencing over a Web-connected television), and internet phones that handle voice-over-IP. Although not shown, it is understood that the described systems incorporate databases for storing information, such as the white-list entries. Thus, a white-list entry is added by adding information into a database; the entry in the database may include information sent by third-party service provider system  206  as well as information generated by CSPA e-mail server system  208 . 
     The third-party service providers, who form trusted relationships with CSPA, share an out-of-band channel between their communications systems and those of CSPA. Using this out-of-band channel and the systems and methods described herein, the third-party service provider may ensure a communications path between two communications user. As depicted in  FIG. 2 , third-party service provider system  206  is connected to CSPA e-mail server system  208  via an out-of-band communications channel  212 . Third-party service provider system  206  is configured to send communications to CSPA e-mail server system  208  over channel  212 , and to receive communications from CSPA over channel  212 . These communications include both data and metadata. For example, third-party service provider system  206  may use these out-of-band communications over channel  212  to notify CSPA e-mail server system  208  that user A1  222  (e.g., a potential buyer on ebay.com) is expecting an e-mail from another e-mail user, such as user B1  228  (e.g., a seller on ebay.com). This may be done even though user A1  222  does not know the actual identity of user A1  222  (see process in  FIG. 9A ). In response to such notification from third-party service provider system  206 , CSPA e-mail server system  208  may add identifying information for user B1  228  to global white-list  224  and personal white-list  226  to ensure that user A1  222  is able to receive e-mail from user B1  228 . 
     Third-party service provider system  206  also is configured to send e-mails to user B1  228  via CSPB e-mail server system  214  and e-mail application system  218 . Thus, third-party service provider system  206  informs user B1  228  that user A1  222  is expecting an e-mail from user B1  228 , and provides an e-mail address of user A1  222  to user B1  228 . Third-party service provider system  206  knows the e-mail address or other information about user A1  222  based on information contained in a registration profile previously filed out by user A1  222  (such as when user A1  222  filed out an ebay.com user profile), or user A1  222  may provide his contact information at the time of indicating a desire for a response from user B1  228  (such as at the time of selecting option  506  of  FIG. 5 ). Third-party service provider system  206  is configured further to send e-mails to user A1  222  along channel  212  or an in-band channel (not shown). In some implementations, third-party service provider system  206  is configured to send additional out-of-band communications over channel  212  informing CSPA e-mail server system  208  that user B1  228  can be removed from white-lists  224 ,  226 . This additional communication may be sent upon completion of a transaction or upon expiration of a specified time period. 
     CSPB e-mail system  204  includes CSPB e-mail server system  214  and e-mail application system  218 . E-mail application system  218 , which is uniquely associated with user B1  228 , allows user B1  228  to read received e-mails as well as draft and send outgoing e-mails. For example, it is configured so that user B1  228  can send an e-mail to user A1  222  over a standard in-band communications channel  220 . That channel may be through a network, the Internet, or the Web. Although not shown, in one implementation, CSPB e-mail server system  214  has a global white-list similar to global white-list  224 , and e-mail application system  218  has a personal white-list for user B1  228  similar to personal white-list  226 . In such an implementation, third-party service provider system  206  may be additionally configured to send an out-of-band communication to CSPB e-mail server system  214  to white-list user A1  222 . This implementation would permit user A1  222  to respond to user B1&#39;s e-mail without having the response blocked by other spam filtering processes. 
       FIG. 3  illustrates that transactional white-listing system  200  of  FIG. 2  may be expanded to encompass any number of CSPs and CSP users. For simplicity, the components of  FIG. 3  that are described in the discussion of  FIG. 2  above (i.e., those bearing numbers  202 – 228 ) are not described again now. Their same descriptions from above apply equally to  FIG. 3 . The illustrated system  300  of  FIG. 3  may be implemented, for example, in the information request context (see sample user interface in  FIGS. 6–7 ). In that context, user A1  222  may request information from a website on a number of different topics. To respond to each of the differing requests, third-party service provider system  206  may notify CSPA e-mail server system  208  of multiple entities that need to be white-listed in global white-list  224  and personal white-list  226 . In the implementation of  FIG. 3 , for example, third-party service provider system  206  sends an out-of-band communication over channel  212  to CSPA e-mail server system  208  identifying each of user B1  228 , user B2  344 , and user C1  338  to be white-listed in lists associated with user A1  222 . User A1  222  would then be able to receive e-mails from each of these white-listed users  228 ,  344 ,  338 . 
     Based on an action by user A1  222  (such as selecting submit option  702  from  FIG. 7 ), third-party service provider system  206  sends e-mails to each of user B1  228 , user B2  344 , and user C1  338  informing them that user A1  222  desires information from them. User B1  228  may then send user A1  222  information over channel  220  using e-mail application system  218  and CSPB e-mail server system  214 . User B2  344  may send information to user A1  222  over channel  220  using e-mail application system  218  and CSPB e-mail server system  214 , and user C1  338  may send information over channel  340  using e-mail application system  336  and CSP C e-mail server system  334 . It is important to note that although each of these channels are shown and referenced as a direct and separate channel, such is done for explanation purposes only. These channels may simply be any connection over a network, the Internet, or the Web. As such, in reality, e-mails from user B1  228  and user B2  344  may not travel over the same channel. 
     Using the example of  FIG. 7  in which user A1  222  requests information related to an upcoming move to a new city, user B1  228  may be an association of realtors, user B2  344  may be a central office for the local schools, and user C1  338  may be the local electric company. Thus, because each of these users are transactionally white-listed by system  300 , user A1  222  can receive the information he needs to plan his upcoming move. Although third-party service provider system  206  may identify each user  228 ,  344 ,  338  to CSPA e-mail server system  208  in one initial out-of-band communication over channel  112 , it may later send separate communications over channel  112  informing CSPA e-mail server system  208  when to remove each user from white-lists  224 ,  226 . 
       FIG. 4  illustrates an implementation in which third-party service provider system  406  itself is the entity being white-listed as a result of out-of-band communications from itself. CSPA e-mail server system  208  is configured to facilitate e-mail between multiple subscribing CSPA users (A 1 –An) and other e-mail users on the Web. These multiple users send and receive e-mails over the Web through their respective e-mail application systems, which are identifiable to CSPA e-mail server system  208 . CSPA e-mail server system  208  has global white-list  224 , and each respective e-mail application systems has its own personal white-lists associated with users A 1 –An, respectively. While global white-list  224  filters received e-mails for each of the multiple subscribing users A 1 –An, the personal white-lists further filter e-mail for only their associated user. Thus, e-mail for user A1  222  is filtered by global white-list  224  and personal white-list  226 . E-mail for user A2  446 , however, is filtered by global white-list  224  and personal white-list  454 . As discussed with reference to  FIG. 2 , third-party service provider system  406  is configured to send and receive communications, including data and metadata, to CSPA e-mail server system  208  over out-of-band channel  212 . As depicted, third-party service provider system  406  uses these out-of-band communications to have itself added to global white-list  224  and to the personal white-lists of multiple CSPA subscribing users in order to send e-mails to the multiple users. This provides a way for third-party service provider system  406  to transactionally provide communications to multiple intended recipients, and to later remove itself from the white-lists. 
     In some implementations, CSPA e-mail server system  208  checks to see whether the white-listed entity is the same as third-party service provider system  406 . If the white-listed party is the same as third-party service provider system  406 , CSPA e-mail server system  208  may add a metadata indicator to the white-lists indicating that some special treatment should be given to e-mails from that entity. Later, when e-mails from an entity having such an indicator is received, they may be visually distinguished or otherwise identified to receiving users as bulk or multiple party mail. 
     Although  FIG. 4  shows CSPB e-mail system  404  located within third-party service provider system  406 , this is done primarily to emphasize that third-party service provider system  406  is itself being white-listed and sending the e-mail. It is understood by those of ordinary skill, however, than CSPB e-mail system  404  may be a third-party CSP (e.g., AOL) that supplies services to third-party service provider system  406  (e.g., amazon.com). As such, CSPB e-mail system  404  may be connected to third-party service provider system  406  via an in-band and/or out-of-band communications channel over the Internet or the Web (not shown). 
     It should be noted that two or more of the illustrated components can be combined or modified without altering the nature of above described systems. For example, although shown for simplicity as separate components of the white-listing systems, CSPA e-mail server system  208  and e-mail application system  210  can be implemented as a single component without altering the nature of the white-listing systems. Because other components, such as databases and routers, are well-known in the art, they have not been described. It is within the knowledge of one of ordinary skill, however, to configure such systems, distribute them over a multiplicity or servers, combine the use of white-lists and other communications filters, etc. 
     II. Example User Interfaces 
     The illustrated system is better understood with reference to an example user interface shown in  FIG. 5 .  FIG. 5  shows an example webpage  500  from third-party service provider system  206  (see  FIG. 2 ). In this example, the third-party service provider is an online auction website, such as ebay.com. The example webpage  500  shows an antique lamp  502  for sale to the highest bidder. The webpage  500  includes a picture and a description of the lamp  502 . Options are provided on webpage  500 , whereby a visitor to webpage  500  may choose to place a bid on the lamp by selecting bid button  504  and/or to ask the seller a question by selecting question button  506 . If the visitor (e.g., user A1  222  from  FIG. 2 ) selects question button  506 , the visitor or potential buyer may then enter the question(s) they want to ask the seller (e.g., user B1  228  from  FIG. 2 ). Because some third-party online auctions do not disclose the contact information of the seller, however, the question submitted by the viewer and the contact information of the viewer is then forwarded to the seller by the third-party online auction system. Such a system protects the seller&#39;s contact information from open publication, and allows the seller to determine which viewers to e-mail in response to questions asked. Third-party service provider system  206  also sends an out-of-band communication to the CSP of the viewer to inform the CSP that the viewer is thereafter expecting a responsive e-mail from the seller. The out-of-band communication identifies the seller to the viewer&#39;s CSP so that the CSP can add the identifying information of the seller to any global and personal white-lists associated with the viewer. The seller may elect then to e-mail the viewer to answer his question(s), which e-mail is filtered through the white-lists and sent directly to the e-mail application system for the viewer to read. Thus, the system shown in  FIG. 2  operates to ensure that the viewer is able to receive e-mail from the seller even though the viewer does not know the identify of the seller (see operational flow in  FIGS. 10A–10B ). Additional information, such as a transactional identifier or an expiration date, may be included in the out-of-band communication sent by third-party service provider system  206 . 
     The trigger for the out-of-band communication additionally may be an explicit option (not shown) presented to the viewer, such as a pop-up window or other interface presented to the viewer after the viewer selects option  506 . For example, this interface may ask the viewer whether he wishes to enable future communications with the seller. It can even provide options to the viewer to permit the viewer to specify and control certain parameters of the transactional white-listing. The viewer can then specify, for instance, that the seller is to be transactionally white-listed for three weeks or until the bid closes on the item the viewer is interested in buying. 
       FIGS. 6–7  shows an example user interface of transactional white-listing system  300  for a webpage  600  for the city of Centerville. Webpage  600  may provide information about the city, including news updates and various options for people to request additional information. For example, webpage  600  includes options  602 ,  604  for viewers to receive additional information about moving to or visiting Centerville. By selecting moving option  602 , the viewer (e.g., user A1  222  of  FIG. 3 ) is presented another webpage from which he may select those items on which he wants additional information. 
       FIG. 7  shows an example webpage  700  listing those items for which the viewer may request additional information. From webpage  700  the viewer may select, for example, options to receive information about local reality agencies, private high schools in the area, and the local electric company. After the viewer checks those items desired and selects submit option  702 , third-party service provider system  206  notifies one or more entities (e.g., users B1, B2, and C1 of  FIG. 3 ) that the viewer wants information from them. Third-party service provider system  206  also sends an out-of-band communication to the CSP for the viewer to inform the CSP that the viewer expects e-mails from the one or more entities. Thus, the viewer may receive e-mails from local realtors, private high schools, and the electric company for the area. Once the viewer receives an e-mail from one of these entities, the disclosed systems and methods may remove or inactivate that entity so that the entity cannot send additional and unrequested e-mail or advertisements to the viewer. 
     Another example user interface is shown in  FIG. 8 . In this interface, a viewer (e.g., user A1  222  from  FIG. 2 ) may visit an online retail webpage  800 . Webpage  800  is associated with an online third-party service provider system  206 , such as amazon.com. The viewer may shop until finding an item of interest, such as a pair of boots, that the viewer wants to buy. After selecting the color and size, the viewer may select an option  802  to purchase the boots. In this context, the viewer may wish to receive e-mails containing shipping and order information from either the third-party service provider system  206  or another entity actually doing the shipping, such as Federal Express or UPS. The viewer may wish to receive such e-mails only as long as necessarily for her to receive the boots; the viewer may not wish to thereafter be inundated with commercial and advertising e-mails from the online third-party service provider system  206 . Similar to the online auction context, selection of the purchase option  802  may prompt third-party service provider system  206  to send an out-of-band communication to the CSP for the viewer identifying either third-party service provider system  206  or another shipping entity. If a shipping entity other than third-party service provider system  206  is identified, system  206  notifies the shipping entity of the viewer&#39;s e-mail address so that the shipping entity knows to send shipping updates to the viewer. These approaches find practical applications in other contexts also, such as, for example, where a viewer purchases an airplane ticket. Using the disclosed systems and methods, the viewer is ensured of receiving flight updates (e.g., flight time changes or cancellations) as needed until the return date of the airplane ticket without opening the e-mail filter door to permit general unsolicited e-mail from the airline or travel website. 
     III. Methods 
     One method of using the described white-listing systems to add a user to global and personal white-lists is described in further with reference to  FIG. 9A . For convenience, particular components described with respect to  FIGS. 1–4  are referenced when describing the process of  FIG. 9A . Similar methodologies, however, may be applied in other implementations where different components are used to define the structure of the system, or where the functionality is distributed differently among the components shown in  FIGS. 1–4 . The method of  FIG. 9A  will be described in the context of an e-mail system; however, as stated above, this process may be implemented in other systems (e.g., IM systems, message boards, caller ID systems). 
     In the illustrated method, CSPA e-mail server system  208  receives an out-of-band communication from third-party service provider system  206  indicating that user A1  222  anticipates receiving an e-mail from another e-mail user such as, for example, user B1  228  ( 902 ). The out-of-band communication often is triggered by an action of user A1  222  indicating the desire to receive an e-mail from another e-mail user. This trigger may result from direct or indirect action by user A1  222 . 
     As discussed with reference to  FIG. 2 , the trigger may be user A1  222  selecting an option  506  to ask user B1  228  a question about an item for sale on online auction website  500  (see  FIG. 5 ). The trigger also may be the purchase of the item via a checkout procedure (e.g., ebay.com checkout). The trigger also may be initiated by user A1  222  visiting information request webpage  700  and submitting a request for additional information via submit option  702  (see  FIG. 6 ). Other triggers initiated by user A1  222  may be online purchases, such as purchasing an airline ticket or buying a pair of shoes (see  FIG. 8 ). The trigger may be initiated by user A1  222  filling out a survey and expressing a willingness to participate further in the survey or by user A1  222  seeking assistance or help from a help or vendor website, or otherwise interacting with the website. Another example in the help website context occurs when user A1  222 , after recently buying a new computer, visits the computer manufacturer&#39;s webpage to ask for help on a particular problem encountered with the new computer. The trigger may be explicit by presenting a selectable option to allow user A1  222  to specifically request that an entity be white-listed. These are all examples of a user taking direct actions to initiate the trigger. 
     In other contexts, indirect user action may initiate the trigger. An example of indirect user action may involve a context where user A1  222  has an established user profile that permits a third-party service provider to transactionally white-list itself whenever certain events occur. For example, user A1  222  may have a Federal Express account configured to white-list Federal Express&#39;s system each time user A1  222  mails a package under his Federal Express account. The account profile may include contact information, such as an e-mail address, for sending the user A1  222  shipping receipts and updates. Advanced options in the account profile may allow user A1  222  to specify an end trigger whereby the third-party service provider system (e.g., Federal Express&#39;s system) is removed or inactivated from the white-lists associated with user A1  222  (see discussion of  FIG. 11 ). Examples of such end triggers include receipt of the package at its destination or the expiration of a set time period. Other examples of account profiles as a part of the present systems and methods include profiles with online retailers or other service providers that indicate the user is willing to receive sales and advertising communications at certain times of the year (e.g., around Christmas or other holidays) or for certain items or events (e.g., sales on classical music or discounts on local sporting events). An indirect trigger in the online auction context might be winning the bid on an item. In some implementations, however, the trigger may be initiated without and independent of any user action. In these implementations, a trusted third-party service provider system may trigger transactional white-listing for unsolicited communications from itself to members of a particular CSP. 
     Returning to the process of  FIG. 9A , after CSPA e-mail server system  208  receives the out-of-band communication sent over channel  112  ( 902 ), CSPA e-mail server system  208  reviews the communication to determine information identifying user A1  222  (the intended recipient), information identifying user B1  228  (the expected sender), and a unique transactional identifier ( 904 ). The information identifying user B1  228  in the out-of-band communication may be any information capable of identifying communications from user B1  228 , such as, for example, an e-mail address, a domain name, a dedicated, static internet protocol (IP) address, a media access control (MAC) address, or any combination thereof. The information identifying user A1  222  in the out-of-band communication may be any information capable of identifying user A1  222 , such as, for example, an e-mail address, a domain name, a dedicated, static IP address, a MAC address, or any combination thereof. The unique transactional identifier (ID) serves to identify the entry to be added to the white-list as a transactional entry. It may be a randomly generated code, or it may be composed of a combination of data or information. For example, the unique transactional identifier may be composed of a combination of data or information identifying third-party service provider system  206  (e.g., a third-party service provider identifier or name), information identifying user A1  222  and user B1  228 , the time/date of the out-of-band communication, and/or a randomly generated code. Other alternative means of generating a unique transactional identifier also may be used. 
     Some implementations may use a generic transactional ID rather than a unique transactional ID. In such implementations, the transactional ID may serve simply to denote the white-list entry as transactional in nature and may be the same ID for all such white-list entries. In addition to the unique and generic transactional IDs, the transactional ID may be one of a subset of defined transactional IDs. Further, all users or entities transactionally white-listed by one third-party service provider system may be given one code while all users or entities transactionally white-listed by a different third-party service provider system may be given a second, different code. 
     Depending on implementation, the out-of-band communication also may include additional information, such as an expiration date (e.g., expires on December 26), timeout duration (e.g., expires in two weeks), or a specified threshold number of received e-mails (e.g., expires after receiving set number of e-mails from user B1  228 ). This information can be used to automatically set an end trigger, whereby the transactionally white-listed user is removed from white-lists  224 ,  226 . For example, if the out-of-band communication specifies a timeout duration of two weeks, CSPA e-mail server system  208  can automatically delete or inactivate the transactional white-list entry upon expiration of the two week period. This may be accomplished, for instance, by CSPA e-mail server system  208  calculating an expiration date based on the specified two week duration and the date of the out-of-band communication. In this example, system  208  may add the calculated expiration date to the transactional white-list entry for user B1  228  in white-lists  224 ,  226 . Subsequent routines periodically may scan the white-lists  224 ,  226  for expired entries and then delete or inactivate them. System  208  alternatively may not delete or inactive the transactional entry until the next time it receives an e-mail from user B1  228 . In such an implementation, system  208  deletes or inactivates the entry upon receipt of an e-mail beyond the expiration date, and handles the received e-mail without regard to the fact that user B1  228  previously was transactionally white-listed. In other examples, the out-of-band communication may indicate that the end trigger should be effected by a subsequent communication (e.g., another out-of-band communication) from third-party service provider system  206 . 
     In addition to the end trigger information, the out-of-band communication may include other information. For instance, the communication may include a “type” indicator specifying a certain enumerated type of communications to be received. That “type” indicator may then be used to provide some special treatment to e-mails (e.g., visually distinguishing them, setting a flag to enable receipt of large attachments) received from that white-listed user. The out-of-band communication may include further information such as a date/time stamp or information identifying the particular third-party service provider system  206  who sent the out-of-band communication. 
     Although the illustrated method of  FIG. 9A  depicts the out-of-band communication as including information on the identity of user A1  222  and user B1  228  as well as a transactional ID, in some implementations the transactional ID may be generated by CSPA e-mail server system  208  instead of being sent with the out-of-band communication. The system  208  generated transactional ID may be generated in similar manner as those discussed for third-party service provider system  206  above. Whether the end event trigger is initiated by the third-party service provider or by CSPA, CSPA e-mail server system  208  may run a program periodically to identity to search and remove all expired or old transactional white-list entries. 
     After determining the identity of user A1  222  and user B1  228  as well as the transactional ID ( 904 ), CSPA e-mail server system  208  determines whether it has a global white-list ( 906 ). This may be determined by, for example, querying a CSPA e-mail server system  208  database (not shown). If CSPA e-mail server system  208  has global white-list  224 , CSPA e-mail server system  208  adds an entry for user B1  228  to global white-list  224  ( 908 ). The entry added to global white-list  224  includes information capable of uniquely identifying user B1  228 . Depending on the implementation of global white-list  224 , that information may include the e-mail address of user B1  228 , the name of user B1  228 , a domain name associated with user B1  228 , or a static IP address associated with user B1  228 , a date/time stamp, and/or an identifier of third-party service provider system  206 . In the depicted implementation, a unique transactional identifier also is added to the entry when created. Also, other information capable of uniquely identifying user B1  228  as the sender of the e-mail received by CSPA e-mail server system  208  may be added. If user A1  222  does not have an associated global white-list, CSPA e-mail server system  208  may create global white-list  224  ( 910 ) and then adds an entry for user B1  228  to newly created global white-list  224  along with the transactional identifier ( 908 ). The newly created global white-list  224  is stored in a database (not shown) identifiable to CSPA e-mail server system  208  so that it may be referenced in the future. 
     In some implementations, such as the illustrated one, an entry for user B1  228  is added to global white-list  224  with the transactional identifier regardless of whether another entry for user B1  228  already appears in global white-list  224 . This may result in duplicate entries in global white-list  224  if user B1  228  already is listed in global white-list  224  as a non-transactional (e.g., permanent) entry. In such a case, user B1  228  may have a transactional entry and a non-transactional entry in global white-list  224 . Such methods save processing time by permitting the addition of the transactional entry without first checking global white-list  224  to determine whether user B1  228  already exists as a permanent entry. In other implementations, the method may first check global white-list  224  to determine whether user B1  228  is already a permanent entry in global white-list  224 . If it determines that user B1  228  is already listed as a permanent entry, the method may end without adding a transactional entry for user B1  228 . This implementation saves storage space by preventing the addition of transactional entries for users already permanently white-listed in global white-list  224 . 
     Next, CSPA e-mail server system  208  determines whether user A1  222  has an associated personal white-list  226  ( 912 ). This may be determined by, for example, checking memory or querying a database containing information specific to user A1  222 . If user A1  222  has an associated personal white-list  226 , CSPA e-mail server system  208  adds an entry for user B1  228  to personal white-list  226  ( 914 ). Otherwise, CSPA e-mail server system  208  may create personal white-list  226  for user A1  222  ( 916 ), and then adds an entry for user B1  228  to the newly created personal white-list  226  ( 914 ). As shown, a unique transactional identifier is added to the entry when created ( 914 ). The newly created personal white-list  226  is stored for future reference. The creation of both global white-list  224  and personal white-list  226  ensures that e-mail from user B1  228  is not blocked by other spam filters operating at the CSP filtering level or at the individual user level. Alternatively, the process may be implemented to add entries only to existing global and personal white-lists and not to create non-existing white-lists. 
     In some implementations (not shown), CSPA e-mail server system  208  further determines whether a global or personal black-list is used to filter e-mail sent to user A1  222 . If a global or personal black-list is found, CSPA e-mail server system  208  checks the black-list(s) to determine whether information identifying user B1  228  appears in the black-list(s). If it does, CSPA e-mail server system  208  temporarily deletes or renders inactive the black-list entry for user B1  228 . The transactional identifier may be used to temporarily disregard or inactivate the entry for user B1  228 . This process is performed for any global and any personal black-list associated with user A1  222 . The inactivating of the black-list entry for user B1  228  may amount to creating an exception specifically for user B1  228 . For example, if a global black-list blocks all e-mail from a domain, such as bar.com, the transactional methods may create an exception for one specific user of that domain, such as foo@bar.com. The process alternatively or additionally may inform user A1  222  that user B1  228  was listed on global or personal black-lists. If informing user A1  222  that user B1  228  was black-listed, the process gives user A1  222  an option to prevent the white-listing of user B1  228 . 
     By virtue of either having the transactional white-list entries override other spam filtering systems or making specific exceptions to black-lists and other spam filtering systems (e.g., rule based systems), the  FIG. 9A  process can be implemented to ensure that e-mail anticipated by user A1  222  is received by user A1  222 . For example, if user A1  222  has a rule that specifies that e-mails without subjects is spam, the transactional white-list process may create an exceptions to the “no subject is spam” rule for an e-mail from foo@bar.com. 
     Although not shown, the process of  FIG. 9A  additionally may first check to determine whether user B1  228  already appears in global white-list  224  and personal white-list  226  before adding an entry from user B1  228 . In such implementations, if user B1  228  is found in white-lists  224 ,  226 , no new entry is added for user B1  228 . This prevents duplicate entries for user B1  228  in white-lists  224 ,  226 . 
     In implementations such as those associated with the system described in  FIG. 4 , it may be advantageous to use the out-of-band communications channel  212  to configure CSPA e-mail server system  208  to receive large attachments in the e-mail or to receive certain types of attachments (such as .exe files). Thus, third-party service provider system  206  may send certain information or requests over channel  212  to effect an opening in a firewall connected to CSPA e-mail server system  208  and thus to permit such attachments. 
     The process of  FIG. 9A  may be applied in host-based or client-based e-mail systems. In client-based e-mail systems (e.g., Microsoft Outlook, AOL Communicator) using client-side filtering, the e-mail application system resides on the user&#39;s home computer or other personal device. In one implementation, the client-side application system checks e-mail filtering rules with the mail server upon connection to the mail server. The rules changes may be communicated over a back-channel using either a push or pull command. Thus, upon connection to a mail server system or after lapse of a specified interval, either the client can request the changes from the server system, or the server system can independently transmit the changes to the client application system. This may be performed using any mail protocol, such as Internet Message Access Protocol (IMAP), Post Office Protocol (POP), or a proprietary protocol. A signature can be applied by the IMAP or POP mail server system that is used by the client-side application system to verify that their host IMAP or POP system is in fact the sender of the rule changes. The additions and deletions to a personal white-list thus are communicated to the client system for client-side filtering. In other implementations, the client-side specified rules are communicated to the server system for filtering of the client-specified rules and other filtering rules (such as the transactional listing of the present methods) on the server system. In such a system the client application system gives deference to the server system filtering. 
     The order of certain events described above can be rearranged without altering the overall nature of the  FIG. 9A  process. For example, although the described process adds an entry for user B1  228  ( 908 ) to global white-list  224  before adding it to personal white-list  226  ( 914 ), such an order could be easily reversed. Similarly, the order of checking a black-list and removing/inactivating a black-list entry could be performed before or after CSPA e-mail server system  208  checks the white-lists. It should also be noted that multiple instances of the process of  FIG. 9A  could run in parallel. 
       FIG. 9B  illustrates another method of using the described white-listing systems to facilitate transactional communications between two users. The process of  FIG. 9B  is an additional or alternate implementation for steps  906 – 916  illustrated in  FIG. 9A . Thus, after receiving an out-of-band communication and determining the identity of user A1  222  and user B1  228  ( 904  in  FIG. 9A ), the  FIG. 9B  process determines whether CSPA communications server system (e.g., CSPA e-mail server system  208 ) has a global white-list ( 918 ). This may be determined in the same manner as described with reference to step  906  in  FIG. 9A  above. If a global white-list exists, an entry for user B1  228  is added to the global white-list ( 920 ). Otherwise, the process determines whether CSPA communications server system has a global black-list ( 922 ). If a global black-list exists, an entry for user B1  228  is added as an exception to the global black-list ( 924 ). This exception prevents the black-list from blocking communications from user B1  228 . After adding the exception ( 924 ) or upon determining that there is no global black-list ( 922 ), the process next determines whether user A1  222  has an associated personal white-list ( 926 ). If user A1  222  has an associated personal white-list, an entry is added for user B1  228  to the personal white-list of user A1  222  ( 928 ). Otherwise, the process determines whether user A1  222  has an associated personal black-list ( 930 ). If user A1  222  has a personal black-list, an entry for user B1  228  is added as an exception to the personal black-list of user A1  222  ( 932 ). After adding the entry as an exception to the personal black-list or if no personal black-list exists, the process ends.  FIGS. 10A–10B  illustrate the flow operation of transactional white-listing system  200  in the context of third-party service provider system  206  and CSPA e-mail system  202  shown in  FIG. 2 . 
     It is understood that one or more of the decision steps shown in  FIG. 9B  (e.g.,  918 ,  922 ,  926 , or  930 ) may be omitted (e.g., to save processing time or when it is known that the condition exists). Additionally, the order of the decision steps may be altered and/or some step may be deleted. For example, the process may check for an associated personal white-list ( 926 ) and an associated personal black-list ( 930 ) before checking for a global white-list ( 918 ) or a global black-list ( 922 ). The process also may omit step  918 ,  920 ,  926 , and/or  928  so that the process adds exceptions to black-lists without checking for white-lists. 
       FIGS. 10A–10B  illustrate the operational flow of system  200  with the first depicted event starting at the top of  FIG. 10A . The flow operation begins with user A1  222  selecting an option on a website associated with third-party service provider system  206  to ask user B1  228  a question ( 1002 ). At this stage, user A1  222  may not know the actual identity or contact information of user B1  228 . In response, third-party service provider system  206  sends an out-of-band communication to CSPA e-mail server system  208 , which it knows is associated with user A1  222  ( 1004 ). That out-of-band communication includes an indicator telling CSPA e-mail server system  208  to white-list a particular user or entity (user B1  228 ) along with information identifying the particular user and the intended recipient (user A1  222 ). The information identifying users A1  222  and B1  228  may be the e-mail address of each user or other uniquely identifying information that can be used in a white-list ( 1004 ). The communication further includes a transactional identifier for use in identifying that specific white-listing transaction ( 1004 ). CSPA e-mail server system  208  associated with user A1  222  receives the communication from third-party service provider system  206  ( 1006 ), and adds the e-mail address of user B1  228  and the received transactional identifier to global and personal white-lists  224 ,  226  associated with user A1  222  ( 1008 ). 
     Third-party service provider system  206  also notifies user B1  228  of user A1&#39;s  222  question and e-mail address ( 1010 ), which notification is received by CSPB e-mail server system  214  (not shown in  FIG. 10A ) and passed to e-mail application system  218  (not shown in  FIG. 10A ) to be read by user B1  228  ( 1012 ). User B1  228  may then opt to e-mail user A1  222  an answer to his question(s) or request(s) ( 1014 ). That e-mail is drafted by user B1  228  using e-mail application system  218  and then passed to CSPB e-mail server system  214  for transmission to user A1  222  via CSPA e-mail server system  208 . Next, CSPA e-mail server system  208  receives the e-mail from user B1  228  directed to user A1  222  ( 1016 ). 
     As shown in  FIG. 10B , CSPA e-mail server system  208  checks for user B1&#39;s  228  e-mail address in global and personal white-lists  224 ,  226  associated with user A1  222  ( 1018 ). Because CSPA e-mail server system  208  previously added the e-mail address for user B1  228  to both white-lists, CSPA e-mail server system  208  finds user B1&#39;s information in white-lists  224 ,  226  and passes the e-mail from user B1  228  to user A1  222  ( 1020 ), who is then able to read the expected e-mail from user B1  228  using e-mail application system  210  (not shown in  FIG. 10B ) ( 1022 ). 
     At that or some later time, upon occurrence of an end trigger event (such as receipt of the message from user  228 ), third-party service provider  206  sends another out-of-band communication to CSPA e-mail server system  208  indicating that system  208  can delete or otherwise inactivate user B1&#39;s  228  information as it is associated with user A1  222  and the earlier specified transactional identifier from white-lists  224 ,  226  ( 1024 ). CSPA e-mail server system  208  receives that communication ( 1026 ) and deletes the occurrence of user B1&#39;s  228  e-mail address associated with the transactional identifier from white-lists  224 ,  226  associated with user A1  222  ( 1028 ). 
     One method employed by the transactional white-listing system to remove entries previously added to global white-list  224  and personal white-list  226  is shown in  FIG. 11 . In the illustrated method, CSPA e-mail server system  208  receives an out-of-band communication indicating that a particular user, such as user B1  228 , can be removed or rendered inactive in white-lists  224 ,  226  associated with the prior intended recipient, user A1  222  ( 1102 ). As discussed with respect to  FIG. 9A , this communication may be triggered by a number of different trigger events. Examples of such “end transaction” trigger events include the expiration of a specified time (which time may be specified by user A1  222 , third-party service provider system  206 , or CSPA e-mail server system  208 ) or the occurrence of a specified condition, such as the receipt of the expected e-mail. Further, such triggers may be specified by user A1  222  in an associate profile. For example, user A1  222  may specify that all transactionally white-listed users remained white-listed until user A1  222  cancels his membership with the third-party service provider system  206  that initially white-listed the various users. Upon cancellation of his membership, third-party service provider system  206  notifies CSPA e-mail server system  208  to remove all transactional white-listings having such a membership-tied end trigger. 
     In some implementations, the trigger event may be provided by CSPA e-mail server system  208  rather than by third-party service provider system  206 . One example of this is when CSPA e-mail server system  208  removes or inactivates an entry for a white-listed user B1  228  upon receipt of an e-mail from user B1  228 , upon expiration of a set duration, or upon receipt of a set number of threshold e-mails from user B1  228 , e.g., without a communication from a third-party service provider system  206 . The threshold may be a single e-mail such that CSPA e-mail server system  208  removes the white-listed user after receiving one e-mail from that user. In such implementations, there may be no out-of-band communications needed to trigger the removal or inactivation of user B1  228  from the white-lists. Rather, CSPA e-mail server system  208  identifies a received e-mail, checks white-lists  224 ,  226  to determine whether the sending user of the e-mail is transactionally white-listed, and if so, increments a counter and compares the incremented counter to the threshold number to determine whether to remove the sending user. Where the trigger is set by CSPA e-mail server system  208  to be expiration of a set duration, system  208  may run a separate routine to determine when the duration is expired. That routine may run, for example, once a day to remove expired entries appearing in white-lists  224 ,  226 . 
     Returning to the process of  FIG. 11 , CSPA e-mail server system  208  determines from the received out-of-band communications information identifying user A1  222  and user B1  228  as well as the transactional identifier used to previously add user B1  228  to white-lists  224 , 226  ( 1104 ). The identifying information is the same type of information discussed with reference to  FIG. 9A  above. CSPA e-mail server system  208  then determines whether the identifying information for user B1  228  appears in global white-list  224  with the specified transactional identifier ( 1106 ). If it finds an entry for user B1  228  in connection with the earlier specified transactional identifier, the entry is removed from global white-list  224  ( 1108 ). Alternatively, the entry for user B1  228  may be inactivated rather than removed. Next, CSPA e-mail server system  208  determines whether the identifying information for user B1  228  with the transactional identifier appears in personal white-list  226  associated with user A1  222  ( 1110 ). If it is found, it is removed (or inactivated) from personal white-list  226  associated with user A1  222  ( 1112 ). Although not depicted in  FIG. 11 , the process may perform an additional check of any global and personal black-lists to determine whether user B1  228  was previously inactivated or removed from a black-list during the transactional white-listing process. That check may be performed by looking for an entry for user B1  228  with the associated transactional identifier in the black-lists. If the process finds such an entry, it may reactivate the black-list entry for user B1  228  by removing the transactional identifier and any other transactional metadata. 
     In some implementations, rather than using a transactional identifier to determine which entries to remove from the white-lists, an entry is simply added and removed for user B1  228  without the use of a transactional identifier and irrespective of whether user B1  228  already appears in white-lists  224 ,  226 . In such an implementation, it may be possible for user B1  228  to appear more than once in the white-lists. This implementation trades the speed of not having to search the white-lists for the transactional identifier for a method and system potentially requiring more storage space to store possible duplicate entries in white-lists  224 ,  226 . 
     Alternatively, the entry for user B1  228  may be converted to a more permanent white-list entry instead of being removed or inactivated. This can be done by system  208  removing the transactional identifier and other metadata that previously indicated that the entry was a transactional entry. The decision to make a user more permanent may be made by user A1  222  or by CSPA e-mail server system  208 . For example, either may specify that once user B1  228  has sent a set number of threshold e-mails, user B1  228  should be permanently added to white-lists  224 ,  226 . The thresholds may be based on an absolute number of e-mails or a rate of the e-mails. The decision to make an entry more permanent also may be made by user A1  222  through a pop-up or other notification informing the user that a certain white-listed person is about to be removed and giving user A1  222  a chance to keep user B1 white-listed. Similarly, an advanced mode window  1200 , as shown in  FIG. 12 , can be used by more sophisticated users to manage their own white-lists. In the illustrated advanced mode window  1200 , users may navigate options to see the transactional entries in their personal white-list  226  and select options to delete entries or make entries more permanent. This process can be implemented in a number of ways. If the user selects an option to make an entry permanent, for example, CSP e-mail server system  208  can remove the transactional identifier from the database entry of the transactionally white-listed user, or it may duplicate the entry without associating the transactional information (e.g., transactional identifier, expiration identifier) Depending on implementation, additional information, such as an expiration date, entry-added date, or the transactional identifier, may be presented in window  1200 . The advanced mode window  1200  also may include the date the transactional entry was added to personal white-list  226  or other such information to assist user A1  222  in determining whether to delete or to make permanent an entry. Furthermore, the system  208  may be implemented to notify user A1  222  each time a transactionally white-listed user is about to be removed from the white-lists and to ask user A1  222  whether the transactionally white-listed user should be entered as a non-transactional entry into the white-lists. 
     Several other implementations of the transactional white-listing systems and methods are possible to transactionally white-list users or entities. In one such implementation, for instance, the third-party service provider system  206  may be a Web browser running on the local computer of user A1  222 . The Web browser may monitor the actions of user A1  222  to observe situations in which user A1  222  may need to receive communications from other users or entities. For example, the Web browser may observe that user A1 clicks on button  506  (see  FIG. 5 ) to ask an online auction seller a question or clicks on button  802  (see  FIG. 8 ) to make an online purchase. The Web browser then may initiate an out-of-band communication with CSPA to inform CSPA to transactionally white-list the appropriate users or entities, thereby ensuring that, for at least a limited time, user A1  222  can receive communications from the transactionally white-listed users or entities. In this implementation, the same methods can be used to perform the transactional white-listing as those described above. 
     Although the described methods add the transactional white-listed entries into a common white-list that includes both permanent and transactional entries, some implementations may use a separate white-list for the transactional white-listed entries. This separate transactional white-list (either alone or in combination with a standard white-list) would override other spam lists and filters used by CSPA and user A1. The above-disclosed systems and method apply equally with such a separate white-list, excepting that the separate transactional white-list would not need a transactional ID as all entries in the list, by virtue of being in the list, would be known to be transactional in nature. 
     As explained above, the transactional white-listing systems and methods can be implemented in many different contexts, such as IM systems, caller ID systems, and message or chat board systems. In an IM system, for instance, instant messages sent to a particular intended recipient may be filtered through a global white-list maintained by an IM host system and/or a personal white-list associated only with the particular intended recipient. The personal white-list may be stored by the IM host system or the local IM client running on the computer or other IM-enabled device (e.g., cell phone, personal digital assistant) used by the particular intended recipient. In one implementation, CSPA communications server system  108  (see  FIG. 1 ) is the IM host system and communications application system  110  is the IM client system of the intended recipient. Likewise, CSPB communications server system  114  is an IM host system, which may be the same or a different IM host system than the IM host system used by the intended recipient. A third-party service provider system thus can effect the transactional white-listing of an IM user through sending an out-of-band communication to the IM host system associated with the intended recipient. Examples of IM systems include, but are not limited to, AIM (America Online Instant Messenger), Yahoo Messenger, MSN Messenger, and ICQ. Additional information on IM systems may be found in “How the Internet Works” by Preston Gralla, which is incorporated by reference. 
     In further implementations, such as those where the same IM host system is used by both the intended recipient and the sending user, the IM host system may add the IM screen name of the intended recipient to the buddy list of the sending user to facilitate communications between the sending user and the intended recipient. The screen name of the intended recipient may be added for only the period during which the sending user is transactionally white-listed. Upon occurrence of an end trigger that removes the sending user from the global and/or personal white-lists, the IM host system removes the screen name of the intended recipient from the buddy list of the sending user. 
     In the context of a caller ID system, the transactional white-listing systems and methods ensure that, at least for some transactional period, an intended call recipient is able to receive telephone calls from a person or entity that might otherwise be blocked by caller ID rules. For example, if a user visits a vender website to receive help on a newly purchased computer or other product, the user may select a “call me back” option to have a vender representative call the user to discuss the problems. The vendor website system may send an out-of-band communication to effect the transactional white-listing of the phone number for the vender representative. Additionally, if the caller ID rules of the intended call recipient would normally block all calls from such a commercial phone number, an exception is created to allow a call to be received from the specified phone number of the vendor representative for a transactional period. The changes made to the white-list, black-list, or other rule filtering systems may be stored on a communications server system responsible for filtering received calls. In one example, such systems use automatic number identification (ANI) data stored at a home unit for monitoring multiple home communications (e.g., e-mail, telephone, other Web-based communications). 
     It will be understood that various modifications may be made without departing from the spirit and scope of the claims. For example, advantageous results still could be achieved if steps of the disclosed processes are performed in a different order and/or if components in the disclosed systems are combined in a different manner and/or replaced or supplemented by other components. Accordingly, other implementations are within the scope of the following claims.