I started to have cards that people one either have a signature or at least with tracking.
I had one guy say he never got the card. He opened a claim against me.
I then went on Canada Post and saw it was delivered and copied the entire string for the tracking from when it left my post office, to the sorting center to when it was delivered.
As soon as I provided this to eBay, they then must have reached out to the buyer, as within 30 minutes of me showing proof to eBay he dropped the claim.
Some people just try to scam you as buyers and people think scammers are on the selling end....