To stop forwarding their mail

[Randomlywondering]

We bought a new house a couple of months ago. The previous owners left a note saying they'd had their mail redirected but in case anything slipped through they'd left a few sheets of printed labels so we could forward it on to them.
We tend to get at least one letter a day. Often official, bank type looking letters. I stick on the labels and around once a week do the 20 minute walk to the post box. Ive now run out of labels. The amount of stuff coming here still makes me think they've not bothered with the redirection or updating their banks etc.
Would it be unreasonable at this point to start returning the mail to sender? No less effort in the short term but hopefully it will eventually stop and the old owners will realise ive stopped providing their free redirection service.

I think I'll forward this weeks mail. Wrote on one that this is the last lot I'll be forwarding and then they can sort it out.
There's nothing really that comes through the post which is irreplaceable and it's becoming a nuisance.

Good move, OP.

Maybe the one of them who was meant to organise the redirection didn't actually bother.
And the other one (not knowing that) gave you the labels as sometimes things don't get redirected if the name is spelt wrongly or the wrong initials used.
Anyway, they've had time to figure it out now.

When we bought a house we got post for the previous three owners. It was ridiculous, especially the catalogue for hardcore German porn that arrived on the day my in laws were visiting. Thank you Mr Jones - also got lots of dodgy gambling schemes addressed to him.

Also got post related to shares owned by the elderly lady who lived there before him, which was quite sad in a way. Found out she was in a care home and passed them on to a neighbour who knew her son, but we still kept getting the letters.