There is a way to "write" the image in the HTML so it wont be an attachment, and I already found a way to do it.
Hmm.. But even if you embed the image into the email, the email client still have the power to not to show the image to the user. Because if it shows the image to the user, then that means the user's ip address is already being sent to the server holding the image. That was what i mean. For privacy reasons, this is not acceptable and i dont think those wel known clients miss such a thing. At least i know that Outlook and Gmail protect users from this.