Thanks Artie. I knew you guys would have a better idea! I was diverted by the idea of a custom action in the Junk preferences and never thought about the separate "Rules" preference. Have now created a Rule which should move FB stuff to the Junk mailbox as a test before changing it to delete instead of move.
It is certainly possible that FB has my personal email for the reason you suggest although I wonder why the message is always about 3 notifications and 7 friends. I'm a little alarmed that I have 7 friends I knew nothing about!
Andy
