The CreateMHTMLBody does not seem to support embeding of PDF file when within an IFRAME syntax. When doing it from the browser, we can see that it generates a much bigger .MHT file as the PDF is embeded. However, this does not work as it requires to download the file because of some weird security issue. I do not think it is possible to embed other thing than images and things like that. IFRAME embeding seems to be something that is related to too much security. Any comment would be appreciated.