I'm a 'mailhandler' in the Buffalo Post Office.
Mailhandlers move mail within a facility and also sort large parcels, mailbags and other containers using forklifts and towmotors and other powered equipment and we staff most automated sorting machines.
I witness first hand the treatment parcels get and I have a couple of recommendations:
1) use registered mail whenever possible. Cost is high, but registered mail is handled seperately from and unlike any other type of mailpiece. Traditionally, the registered mail departments are staffed by senior clerks who are likely to be more gentle with your parcel than any other service. Registered mail pieces are given their own container and are segregated from the rest of the mails and are constantly kept under lock and key, transferred hand to hand at all transfer points and constantly tracked within the system down to the names of each clerk who has touched it.
2) Double box. Peanuts are not recommended for the initial packaging of your delicate electronics. Seal the item against water damage by wrapping it in a large, thick trash bag then bubble wrap several layers and fit snugly into 1st box lined with styrofoam, 1/2 inch thick. Put a layer of about an inch to two inches of peanuts into the second box, set your package in it and completely pack with peanuts as tightly as possible to eliminate voids, forcing peanuts along sides and into corners. This acts as a shock absorber and helps to lessen the stress on the item should the parcel should be dropped.
So many people have blamed carriers for damages when in fact the damages can be traced to poor packaging and claims denied for that very reason. If your mailpiece is valuable, don't skimp on the shipping.
definition taken from the officail Postal guide to mail handling:
FRAG-ILE - from the latin frag or fragment: to break into a million pieces; and ile: with total malice or ill will.