The ContentID property returns or sets the Content-ID header of a MIME (Multipurpose Internet Mail Extensions) message body. Read-only.
objAttach.ContentID
String
The ContentID property is used for MHTML (MIME HTML) support. It represents the Content-ID header for the appropriate MIME body part.
The CDO for NTS Library does not generate Content-ID headers for outgoing messages or attachments. This property is provided to inspect an incoming message for Content-ID headers.
For more information on MHTML, see the RFC 2110 document.