Do the Post Office people mark the parcel "delivered" (1) when it leaves the post office with the carrier, or (2) is it scanned "delivered" by the carrier when he puts it into your mail box?

The tracking for the insured parcel being sent to me in Brooklyn is marked "delivered", but it wasn't downstairs in my mail box or with the doorman. Humph! (One odd thing on the tracking picture: the bottom entry says Dec 23, but I first corresponded with the seller (by email) on Dec 26th.)

Robert