Here is the thing I was told about Delivery Confirmation by USPS, which is the "tracking #" you see when you pay on e-bay and things have been shipped.
"Delivery confirmation is not tracking. We are not required to scan it until it is delivered. If you want tracking you need to get express shipping and ask for tracking."
That was what I was told when one of the swap ponies I sent out disappeared for several weeks before turning up damaged at it's final destination. I was told that it looked as if the bubble shipper had been punctured repeatedly. I am sure that if I hadn't wrapped the pony in bubble wrap before putting it in the bubble shipper, more than just a tassel would have been damaged.
I am not sure what has been going on with USPS but I've stopped using them to ship ponies since every pony I shipped out along with the swap pony, regardless of how well it was packaged or weather it was in a strong box or a bubble shipper went missing for several weeks, despite DC; And arrived broken in some way.
FedEx has been what I'm now using. It has it's own flaws. It's more expensive, they are closed on weekends, and if they can't get someone to sign for the package and they don't feel the package is safe to leave on the door step, they will bring it back to the office.
However, I appreciate that they are so committed to making sure the recipient gets it that they will make sure it's safely delivered, not just leave it on an unsecured door. And the things I've shipped using FedEx have all arrived safely and their tracking actually is tracking!