How about sending them a check for $0.03? Maybe no one would care, but it would cost them money, I’m sure.
You could whip up a short note saying you’ve made a donation of $1,000 in their name to AOC’s re-election campaign. Or pick some other left-leaning politico of your choice who the RWs love to demonize.
Whenever you get a business reply envelope from the RW demand-o-sphere, just slip a copy of your note into it and drop it in the mail. You’ll get a chuckle, even if the drone who opens the mail just smirks as he tosses it.
Maybe, just maybe, this’ll stop a few repeats later.
I got several pieces of mail like that from my late mom,
I used to fill out the form that donors are supposed to fill out with an obviously fake name, something like Trumps Big Fatass and a fake address and phone number, something like 123 Trump Sucks Road, then I’d put it in the return envelope and send it back, without a donation check, of course.
Just a little bit of harmless petty prankery, but it felt good.
Pettiness has its virtues, and a great sense of satisfaction can be achieved.
IMO that’s all pettiness is good for, the personal satisfaction.
It’s not going to make a difference to the target of your pettiness, but if it makes you feel better, go for it.
I still get junk mail addressed to my mom, who died 3 years ago, my wife, who died 8 years ago, my sister, who died 9 years ago, and my father, who died 24(!) years ago. It’s annoying but I just toss them. I expect that hundreds of years from now, mail addressed to them will still be arriving.
He (@hajario) is not wrong.
mmm
Or as Spinal Tap said -
I’m looking for pound notes, loose change, bad checks, anything
You would get on a donors list.
Would sending them really bad Dad jokes make you feel any better? It wouldn’t hurt the folks sorting incoming donations, but might slow them down a little, causing the assholes in charge to spend a few more cents on sorter salaries.
It would sort of turn the return envelopes into fortune cookies.
Send the material from one back in the envelope of another.
I just wanted to make a point I only halfway made before:
While it’s TRUE that dad never lived at this address, and that I moved here the next calendar year after he died, we (mom and I) still have title on DAD’S ACTUAL HOUSE.
Why on earth is the RNC sending his junk mail TO MY ADDRESS and not HIS ACTUAL ONE?
This is the kind of fact that makes me feel dedicated to some comeuppance, or sense of satisfaction.
I also wanted to reiterate that many people here who claim “nothing can be done” didn’t try hard enough.
So back to not fighting the hypothetical for the OP, while I still stand by my prop money selection, if you want to change it up a little, I’m sure a “Cthulhu 2024 - Why settle for the lesser of evils” or an Idiocracy Camacho for president sticker or printout in addition to / instead of the prop cash would be worth a chuckle.
Especially for Cthulhu, they’re halfway there already… 
Is the estate settled? Do you no longer get legitimate mail for him? If so, this could be the answer:
DadColossus moved to Mar-a-lago, didn’t he?
I nearly spit a mouthful of burrito across my screen. Well done, sir.
Business reply mail costs over two bucks in postage. I would just keep sealing the return envelopes and sending them back empty, with the satifaction of knowing that I am costing them a fair bit of money and they cannot tell why (in most cases, even who).
I think some of us are claiming nothing needs to be done.
mmm
Most of us here are old enough to have dealt with a death in the family. And the emotional aspects of the administrative mess a death leaves behind.
What many of us probably have not dealt with is the extreme degree these charity fund-raising demands can get to when the victim has built up a large enough profile as an easy mark.
My Mom died suddenly of a heart attack. The day before that she was fully involved in local R party politics as a volunteer and was a rabid disciple of the Hannity/Limbaugh cult. I’m not proud of that fact, but it is a fact and relevant to the story.
She was receiving 4 RW magazines and a dozen donation solicitations in the mail every single day. For the first 6 weeks or so a book she had ordered (and paid for) arrived almost every other day.
Once we’d cleaned out her residence, I opened a PO box for her estate in the different state where I lived. We gave no forwarding instructions and somehow the donation-o-sphere connected the dots and the crap appeared en masse in our new PO box. Every day the box was filled and if I missed a couple days to go fly a trip the UPS store had a carboard carton full of stuff to give me because the mailbox was stuffed and crap kept on coming.
It took months of effort to slow that to just a couple donation demands per day. 3 years later closed the box. Up to the last day we still got donation demand stuff for her a couple times per month. Their systems are simply not designed to ever give up on someone who was once a real patsy.
But it’s a valid response to the rest of the post, which ignored the OP and offered a lecture.
The OP made it clear what he was asking for. It’s in the title and everything. And the post even flat out says they know it won’t do any good, but they don’t care. So lecturing them about how what they are doing won’t do any good makes no sense.
“How is this harassment?” is literally the first sentence after the offered condolences. That’s a lecture. Furthermore, the OP covers that: because they’ve directly tried to cancel and they refuse to listen. Most consider that unacceptable even when it happens with email, let along regular mail.
It’s not like we’ve not had these types of threads before. None of us expect they will actually go through with any of the suggestions. We’re just helping the OP vent.
Not telling them they’re wrong to be angry.
The irony of you criticizing someone for giving a lecture is too funny not to point out. I’ll make you a deal, let’s both not give unsolicited lectures ever again. OK?
To the substance of your post, I didn’t say that they were wrong to be upset. My point was that it is impossible to get back at the actual people and that any revenge technique will make innocent people suffer.