Rstringer, I think the letter 'I' in the term 'Img' that comes before the 'https' and the full link has to be a little 'i' and not a big 'I' I think if you fix that it will embed the picture. When I'm in the message full screen editor, I always hit the 'preview post button to make sure the embedded picture truly embeds before posting the message. See if that works for you.
