The USPS Delivery Confirmation will update as the package goes through the system and show different PO locations that it's at.
But, as stated already,,it depends on the thoroughness of PO emplyees to scan the package and at delivery point it's just another scan and placed on the door step or mail box. Unless there is a signiture required card, insurance for over $200, etc,,no signiture of recipient is required to be obtained by the PO.
The signiture delivery confirmation from insured packages over $200 isn't available on-line. You can get it by going to the PO itself and they can retrieve it from the Way-Back Machine in the back room.
Even with all that I've had at different times had signiture required packages from all 3 carriers dumped w/o them getting one.
They're all great till they loose or break something on you....
Short of self delivery,,,we haven't much choice other than to pack well, insure, use lots of tape and pray.