We have had mail theft issues since the house was built by my parents in 1961. It caused us to take down our street mailbox and to get a PO Box at the local post office (USPO). We never lost a package for years after that. We live with 2 other houses on a driveway that is 1/8 of a mile from the street to the house at the top. We cannot see the road nor where the mailbox was. Then my mother passed in early 2013 and I was the executor of her estate. NY state would not permit the use of a PO Box address for an estate and we had to put the mailbox back up.
Soon after I ordered a bunch of plastic hose fan spray heads, ball valves and splitters for use on tanks. I let it be delivered to the house via the mailbox. When I got the email saying it had been delivered, I drove down to the mailbox and found nothing. We and the home in front of us for mail delivery both had our mail stolen that day. I filed a police report as did the neighbor.
We still have the mailbox on the street but I get no mail there, it all comes to my PO Box and I pick it up. The problem now is Amazon, When I order something small enough, they stuff it into the mailbox. It may be a few hours before I check emails and I then see the email saying they left the package in the mailbox. So far nothing has been stolen, but it is just a matter of time as far as I am concerned.
Here is one thing I have learned over the years. People will steal anything and everything. Even a box filled with poop will get stolen if it is sitting where it can be seen.
When I buy fish they always come overnight and are delivered to the front door. It may be via FedEx or UPS. When it was still possible to feel safe shipping fish via the USPO, I had them sent to my PO Box. The nice thing about this is the box is sitting indoors until I go get it. Plus, the USPO does not leave mail on the trucks overnight. It is brought inside. Unfortunately, the post office is no longer a reliable way to ship fish.