In the Netherlands too unfortunately, and this is being abused on a small scale by companies with bigger pockets to just purchase an advertising package from the privatised Dutch post (PostNL they are called nowadays), and have them deliver spam with your address and 'to the residents' on it. It's a spam loophole politicians so far have refused to close, and which PostNL defends as being perfectly legal and part of their business offerings. I think I get one of those each month — it's much more expensive to send than normal flyers.

I've started an experiment with these: I just repost them in the postbox and see how many times they come back to me. You can always put them in the postbox with a 'return to sender' on it, but if you leave it as is it seems to come back to you like a paper boomerang. I've had one round-trip now for UberEats; I wonder at which point it'll get taken out of circulation?