I’ve not seen any “all” claim but per the NYPost the stamps on the one sent to Brennan weren’t postmarked.
It has been confirmed that the Brennan/CNN package was hand delivered. I have raised the point that I do not see any sane postal clerk accepting these packages at a post office counter. And if they had been dumped in a drop box, they all would have been return to sender, not just the mis-addressed Holder one. If they truly got into the Postal Service system, that IMO is a red flag right there.