Did you try to make the attachment contents id value the same as the one
used by Outlook?
Did you compare the two messages in the Sent Items folder with OutlookSpy or
MFCMAPI?

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

wrote in message
oups.com...
I've reduced the HTML body to the simplest form possible:

IMG src=cid:image1

and still the image gets stripped. I'm setting the following
properties on the attachment:

attachment.set_Fields(0x370E001E /*content
type*/, "image/jpeg");
attachment.set_Fields(0x3712001E
/*PR_ATTACH_CONTENT_ID*/, "image1");

is there any other property that should be set?