US Patent 7877594 Method and system for securing e-mail transmissions

A method for frustrating unauthorized access to an electronic mail message having address, body and attachment information and being transmitted from a first computer to a second computer, including: at the first computer: detecting a request to send the message; encrypting the extracted body information; replacing the extracted body information with the encrypted body information; extracting the attachment information; encrypting the extracted attachment information; replacing the extracted attachment information with the encrypted attachment information; returning the message having the encrypted body and attachment information to the mail user application; and transmitting the message having the encrypted body and attachment information to a third computer; and, at the third computer: decrypting and re-encrypting the transmitted body information; decrypting and re-encrypting the transmitted attachment information; and, transmitting the re-encrypted body and attachment information to the second computer.