Patent ID: 7483949

Claim:
A method for caching e-mail data over a network, comprising: storing e-mail data on an e-mail server at a first network location; accessing the network with a client at a second network location; retrieving a site local e-mail message caching device (EMCD) IP address table with the client using IP address table information stored in a user's mailbox; comparing a network location of the client to the site local EMCD IP address table; and selecting a site local (EMCD) for caching the e-mail data from the e-mail server based on the network proximity of the site local (EMCD) to the client; said comparing comprising the steps of: parsing the IP address table to retrieve at least one IP address record for a given (EMCD), wherein the IP address record includes at least one IP address/mask pair of an (EMCD); wherein for each IP address/mask pair retrieved: performing a first bitwise AND between a client local address and the mask of the address/mask pair; performing a second bitwise AND between the table address and the mask of the address/mask pair; comparing a resulting value from the first and the second bitwise AND for a match; and in response to a match, including the table address in a resulting list of potential IP addresses for the site local (EMCD); if there is no match, the address is discarded from consideration.