The GetStream method returns the Stream object that contains the complete message, including headers and all content, in serialized (wire-transport) format.
Function GetStream() as ADODB.StreamHRESULT GetStream(_Stream** pVal);
The GetStream method returns the entire message, including its headers and content, including all body parts if the message is formatted in Multipurpose Internet Mail Extensions (MIME), as a serialized stream within a single Microsoft® ActiveX® Data Objects (ADO) Stream object. To obtain a stream for one of a message's body parts, call the GetDecodedContentStream or GetEncodedContentStream method of that body part object.
The stream returned by this method is essentially a serialized copy of the current message as it existed when this method was invoked. All changes made to the Stream object are local, and the message itself is not updated until the stream is flushed back when you call the Flush method on the ADO Stream object.