Rapidly obtaining a subset of message data from a server for filtering

In a computing network comprised of a plurality of interconnected servers for transferring messages among the interconnected servers, and wherein at least some of the servers use a communication protocol that is not configured for communicating filtering information to the server, and wherein the computing network also comprises a plurality of client side computing devices for accessing the servers and downloading messages, a method of using client-side tracking mechanisms to allow a client side computing device to efficiently determine which messages need to be downloaded from the at least some servers for filtering at the client side computing device, so that essentially most of the filtering operations occur before the messages are downloaded, the method comprising:

• setting at a client side computing device a filter criteria for new messages;
• receiving at the client side computing device a list that identifies all messages maintained at least one server using a communication protocol that is not configured for communicating filtering information to the server;
• retrieving at the client side computing device a message store table that contains records identifying each message which has previously met the filter criteria and has been placed in a message store, and marking each record with a flag;
• retrieving at the client side computing device a checked table, the checked table comprising records identifying each message which has been checked against the filter criteria and has been found not to meet the filter criteria, and marking each record with a flag;
• comparing the messages identified in the received list for all messages maintained at the at least one server with the records contained in the message store table and, for each message, determining if the message has already been placed in the message store;
• comparing the messages identified in the received list for all messages maintained at the at least one server with the records contained in the checked table and, for each message, determining if the message is in the checked table, the checked table comprising records identifying messages having already been checked against the filter criteria and having been found not to meet the filter criteria;
• then downloading to an inbox at the client side computing device all messages from the list that do not already correspond to a record in either the message store table or the checked table, so that download time is limited only to all new messages as determined from the message store table and the checked table;
• unmarking the flags for all records contained in either the message store table or the checked table that already correspond to those messages identified in the list that have been previously identified in either of the tables;
• checking all new messages downloaded against the filter criteria, and either adding a new unmarked record to the message store table if the filter criteria is met, or else adding a new unmarked record to the checked table if the filter criteria is not met;
• and
• removing any remaining records with marked flags in the message store table and the checked table.