This video introduces you to Active Directory Rights Management Services by showing you how an end user can protect and assign specific permissions to an e-mail message.
Read more at source: http://edge.technet.com/Media/Protecting-an-E-mail-with-AD-RMS/
Cheers,
Anderson Patricio
http://msmvps.org/Blog/AndersonPatricio
http://www.andersonpatricio.org
Twitter: @apatricio