I ordered some books from Amazon. After a couple weeks I logged in to get a delivery status update, and it said that the package had been delivered several days earlier. The Amazon seller told me the package was delivered. So I opened a lost package inquiry with the post office. After a few days, someone from my local branch left me a voicemail to tell me the GPS coordinates indicate that the package was delivered to some town in Texas.
And that was it. There was no further attempt to recover the package. And they even knew exactly where it was! The post office does not stand behind anything. You basically need to buy insurance for every little thing you ship. Fortunately the Amazon seller gave me a refund even though it wasn’t his/her fault. I would avoid using the post office for anything important if you have that option.