Forefront Online Protection for Exchange can help you protect sensitive information in your organization with policy encryption rules, which encrypt e-mail messages based on policies that you configure in the Administration Center.
This video will show you how to create encryption rules and how they can be used in your organization to protect critical information sent through e-mail.
Watch it out at: http://edge.technet.com/Media/Encryption-Policy-Rules/
Cheers,
Anderson Patricio
http://blogs.msexchange.org/patricio
Twitter: @apatricio