Images in signatures are notoriously problematic. It's much better in HTML format because HTML was designed to support in-line images. RTF isn't. Even in HTML format though you can't guarantee how the recipient is going to see your message - if they're using Outlook you have a pretty good idea of how it will render, but if they're using Thunderbird, Notes or some obscure 3rd party e-mail client it could do all sorts of wacky things with your images. Plus some systems still force incoming HTML messages to plain text or RTF. So even if you send as HTML you can't guarantee it'll be received as HTML. That problem is 20 times worse in RTF which really isn't designed for in-line images. I guess I'm not really giving you a solution here - other than don't rely too heavily on images in e-mail signatures, especially if you can't guarantee all of your messages will be sent AND received as HTML.