I buy used boxes and packaging to minimize and recycle as much as possible. The packages are always very well secured, but just in case, for a delivery to a relay point with Mondialrelay, if the package is damaged, such as a hole or dent for example, you must open it on the spot (that is, at the relay point) to check the condition of the package. If the item is broken, it will be due to Mondialrelay only, so tell the merchant that you refuse the package in order to activate the insurance. This has never happened yet, but these are the conditions for damage with Mondialrelay.
I always take photos of the package when it leaves for the relay point, once the printed label is attached to the package, to show the condition of the package at the start.