It might or might not be impossible. It *is* impossible on rawbody, since the rules only see one line at a time. It might be impossible on full, if the message is encoded, since full will see the encoded text. It may or may not be impossible on body, depending on the version you are running and a handful of other things.
Sometimes body gets broken up into multiple pieces, making it nearly impossible to do anything that spans multiple lines. In HTML, a <br> will do this, as occasionally will a <p>. In plain text, sometimes it will break the body on multiple lines, sometimes not. Try the rule with /s on the end of the re. That will tend to turn newlines into spaces. Loren