A method is employed to propagate rights management (RM) protection to an email and to an attachment thereof comprising an RM-protectable document. The email with the RM-protectable attachment is authored, and a content key (KD) and a bind ID are generated. RM protection is first applied to the RM-protectable attachment of the email based on the generated (KD) and the generated bind ID, and the RM-protected attachment is attached to the email. RM protection is then applied to the email with the attached RM-protected attachment based on the generated (KD) and the generated bind ID. The RM-protected email and the RM-protected attachment thereof thus share the generated (KD) and the generated bind ID such that a license obtained for the RM-protected email and having therein the generated bind ID and the generated (KD) can be applied to render the RM-protected email and also the RM-protected attachment thereof.