If like me you get fed up of junk mail & have registered online at MPS, but still find the postie delivering un-addressed leaflets / letters, then do the following .
Send a letter to the follwing address, stating you no longer want to recieve un-addressed leaflets at your home address (don't forget to include your address

) :-
Door to Door Opt Outs
Royal Mail
Kings Mead House
Oxpens Road
Oxford
OX1 1RX
Mines in the post already