US Patent 8640201 Mail server coordination activities using message metadata

In a distributed electronic messaging system authorized information comprising metadata concerning a message is passed along from one mail server to another mail server. A receiving computer determines if the sending computer has the necessary authorizations to pass along the metadata. If so, the authorized information is passed along with the message body, enabling repetitious actions to be eliminated. If the sending computer is not authorized to pass along the metadata, the metadata is stripped off the message, changed or annotated.