2.1.3.5 Generating Pure MIME Messages

 When generating pure MIME messages, MIME writers SHOULD<104> combine stored Message object content with the contents of the PidTagMimeSkeleton property ([MS-OXCMSG] section 2.2.1.28). The purpose of the MIME skeleton is to make the MIME output more accurately resemble the original MIME message when using the messaging server as the conduit between two MIME-based protocols, such as SMTP and POP3 or IMAP4. The MIME skeleton contains the MIME structure and the headers of the original MIME message without any of the body part content, with some exceptions, as specified in section 2.3.

To generate a pure MIME message, the MIME writer reads the contents of the PidTagMimeSkeleton property associated with the Message object, and then generates the pure MIME message by combining the contents of the skeleton with the saved Message object content and attachments. The coupling of the generated MIME message to the original saved message by using the skeleton enables a more accurate reproduction of the MIME message provided by the server to clients. For more details about how inbound MIME content is stored and saved, see section 2.3.

The behavior specified in this section applies only if the PidTagMimeSkeleton property is defined. If it is not, MIME writers MUST follow the guidelines set forth in sections 2.1.3.1, 2.1.3.2, 2.1.3.3, and 2.1.3.4, in that order.