Thank you letters

It's nice to get an acknowledgement that the gift has been received and is appreciated. Sadly it doesn't always happen. Personally I always send a thank you text for tea and a biscuit, let alone an actual gift
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but are these people who give you gifts ?
if not maybe they don't really want you to keep giving them gifts, they don't want the implied indebtedness, so they don't want to encourage it by sending thanks.
i don't really want xmas cards, so i stopped sending them. gradually the cards to me petered out. success.

Message withdrawn at poster's request.

Yes, same here. My (slightly tricky) DIL never thanks or even acknowledges birthday gifts, even by text.. They live some distance away so often have to be delivered. This year got”sniffy” text from DS “PS it was L birthday yesterday” when online gift presumably sent mail hadn’t arrived as estimated because of strikes. Spent next 2 weeks organising replacement only to find it had been delivered 2 days ago. Don’t want to stop giving gifts to DIL as I would others. How to broach subject?

You are right to be cautious GranJan60 leaving out a daughter or son in law would cause family rifts. However I think you could use the late delivery example to ask for a response when gifts are received.
I don't think many people send thank you letters or cards now but an email or other electronic message would be easy to send. I would be really annoyed if my family didn't respond to a gift. My husband's family though that's a whole different ball game.