Can any of you SA/Surbl gurus tell me where I can change the scoring of this rule?
(I assume, probably incorrectly that this is a Surbl rule...) ;)
Indeed you did :-) It would be better asked over on the SpamAssassin users list.
The default score is in the 50_scores.cf file, usually located in /usr/share/spamassassin depending on your OS and installation type etc etc.
Don't modiy this file, just override it by specifying a different score in your local.cf
Regards,
Joseph