Did you figure out this problem? I was trying to do the same thing and I couldn't figure it out. I've found an answer though. You need a shared workgroup and everyone has to have access to this workgroup for them to see it. Regarding as to why you don't see the images when you test sending/receiving, you must have Outlook send/receiving in HTML mode otherwise the image just comes as an attachment. You probably need to set-up S/MIME actions in your Outlook also.