These things annoy me.
People working in corporate marketing departments think it's okay to by and sell random people's personal information. While addresses themselves cannot, by definition, be private, the combination of address plus the name of the person living there that becomes private information. These people think it's okay to sell this information to other companies, when I've given my name and address to them, what I thought was in confidence, in order to do business with them.
While it's conceivable that the Deeds Office records are public, I don't for a moment think that corporate marketing departments get their spam list there. That's too much work. As is scraping the Internet for random occurrences of names and addresses, like in my Curriculum Vitae.
See also my spam-specific shit-list.
It's much harder to catch these shits. Harder still to show beyond reasonable doubt that it was anyone in particular. Still, there is a method: mutate your address ever so slightly whenever you give it to anybody. Record who gets what mutation, and then compare this list to addresses printed on junk mail. That should narrow down the list of suspects. You will have to combine several elements to get a useful spread of mutations. If you have an unusual and complicated name like I do, use that too!
For example, I might live at any of these addresses (not using my real address for this example):
I don't know if the postman will play along with all these variants. There are some pretty extreme stories out there about postal workers making sure that mail arrives at its intended destination, but you might not want to rely on that. On the other hand, do you really care if your bills fail to arrive once in a while? Just be honest and pay what you know is due, and you should be fine.