Systems and methods are described for enabling documents to be controlled
by a sender, in a manner which is transparent to any end recipients. The
invention include mechanisms enabling a sender to control documents sent
to recipient, in a manner that (1) encrypts the message to ensure its
security, and (2) restricts operations the recipient may perform on the
received message. The recipient and sender need not agree on a control
protocol in advance of the communication. Wide distribution of a Digital
Rights Management System may be facilitated by use of self-installing
modules, which integrate with existing software used for document
publishing and retrieval. The modules are forwarded to unregistered
recipients upon authentication of the recipient, and install
automatically on the recipient's computer. The modules authenticate
instructions from a sender, and, per instructions from the sender, may
pre-empt certain types of operations on the e-mail by the recipient
