My father tries to forward an email and the second he does this the pictures are greyed out. thusly when he sends them on we get a box with a red "x" in it. Is there a setting or anything in Mail that will stop this from happening??
What version of Mac OS X and Apple Mail.app are you (or your father) using? Is it an HTML-formatted or RTF-mail message? What happens if you - instead of forwarding - create a new message and drag the pictures over?