Looks like Wigan Metro are doing their job as I am not on it, but an old girlfriend who owes me some money is!
Having said that I have also registered with the Mail Preference Service, takes about 3 months to kick in but then it becomes an offence to send junk mail to your address.
http://www.gov.im/dlge/waste/tips/home/junkmail.xml There is one for unwanted calls also.