2.2.3 Attachment Object
A rights-managed email message consists of a wrapper email message with the original email contents encrypted and compressed in an attachment. The attachment that contains the encrypted, compressed contents of the original email message SHOULD be the only attachment on the wrapper email message. If the wrapper email message includes multiple attachments, the attachment that contains the encrypted, compressed contents of the original email message MUST be the first attachment. This attachment has specific property values, as specified in section 184.108.40.206 through section 220.127.116.11, that distinguish it from the other attachments. For details about the procedures for encryption, compression, decompression, and decryption of the original contents in the attachment, see section 3.1.4.