SMTP extension to preserve per-message and per-recipient properties

摘要

The SMTP protocol takes a message formatted according to a defined internet standard and wraps the message in an envelope. The message and envelope are sent to servers for transfer through the Internet to their intended destination. The SMTP protocol strictly defines the information that is transferred in the envelope and the format of the message. There is thus a real possibility that when messages are transferred from one network into an SMTP network that information will either be lost or not transferred correctly. The present invention provides systems and methods that take advantage of defined mechanisms to extend the SMTP protocol in order to create the novel extension that allows the transfer of virtually any information after the envelope is transferred but before the message is transferred. The invention allows information usually contained in the message portion to be transferred in the envelope portion. The invention also allows the preservation and transfer of information that would otherwise be lost.