We have cluster mailboxes outside the gate. So USPS never comes in the gate. FedEx will, Amazon will, UPS will. But not the post office.
There are large lockers in these cluster mailboxes that packages can fit in and the key will be put inside your mailbox. But USPS Service where we live is poor and inadequate and they have just about given up on delivering packages even to the cluster mailboxes. So they just leave it at the post office.
Our cluster boxes are also outside the gate, but everyone still comes inside, including the Post Office. I see their trucks all the time. Apparently the PO still delivers in my area. Hopefully they won't stop, because a lot of stuff still comes through them.