I'm pretty sure it's a local issue on your machine, then - more to the point, with Outlook and/or its settings. The Gmail copies showed the images, so it happens upon retrieval, not upon send (i.e. it's not something the Cameraderie server is causing if you ask me).
The Gmail thing (retaining copies) may be due to the protocol used, but I've all but forgotten the deails. IMAP/POP3? I think you're seeing the default behaviour of using IMAP here. Not that it matters (much) with Gmail ...
M.