Mail addressed to former owners

I'm with other posters on here. What a cheek these people have. Put their mail back in the mailbox at your own convenience with Gone Away, or Not At This Address on it. And let them know that's what you intend to do.
We had a similar issue when we moved to our present house. The previous owners obviously didn't want to be found and we had no forwarding address for them so I would keep a big fat red felt tip pen to note their mail with Gone Away before it went back in the post box.
After years of getting mail from LLoyds bank I finally rang them to let them know we had been owner occupiers at this address for 6 years and I had been returning every letter they posted here. Their response was that they were legally bound to send post to the last recorded address. I said that in my earlier role as civil servant if a customers mail was returned DLO (Dead Letter Office) we would suspend the account pending customer contact. I also said that in future i was returning no more mail and it would be binned. That did the trick as we had no more.

That's appalling sunseeker. Personally I would text back and say I have reached the end of my goodwill, I will not be forwarding your mail in the future.

I've been here for nine months and in the initial six months had a huge faff forwarding post to my vendor, she had only paid for three months redirection.

She then ordered a router and they sent it here. I texted her and she arranged for a 'special envelope', and I had to make an unplanned trip to the PO to post it off. Luckily nothing this week apart from a Saga letter that I've 'not known at this address'.

I had this with the previous owners of my house. I have lived here for 26 years and yet still a letter from an insurance company arrives for them although I have put "No longer at this address" on the envelope for about 10 years and stuck it back in the post box.

I would reply stating you will no longer hold or forward their mail to them. That you will be posting it all back with no longer at this address attached.

After a while I just binned all mail that came to us that wasn't addressed to us.

What a cheek! For a start they should have informed their bank (and any other important org) of their new address, and secondly, should have arranged redirection with the post office.

I would politely but very firmly suggest they do both the above ASAP, and add that you will be forwarding any further mail at your own convenience.

I would write’Gone away’ on it and pop it in the post box. Very strange they haven’t informed their bank that they’ve moved.

Definitely go with your last sentence.
They are taking the proverbial! ( is that the correct spelling ?) I wanted to put the actual word beginning with a P & ending in S.?