So I know some of you dislike 123 Reg, but I have to say their implementation of a fraudulent email reporting service deserves a pat on the back. At least they're taking responsibility for scams perpetuated in their name. Most organizations tell you it's not their problem and to report it to a government body.
http://mail.123emailmarketing.co.uk/l/c.php?c=40641&ct=23435639&si=66685558