I've been shipping and receiving 'small boxes'Al
Back and forth to and from Germany for decades. Here's what I've found out:
The USPS and the Bundespost do not handle 'signature required' or any form of receipt based package/letter well. Many times, a family member in the US would send me something important with 'receipt requested' and it would be returned to the US - after a delay of about six weeks. Never, not once, did such a package/letter arrive. Not once.
The reverse? Cost hundreds of Euros and failed nearly every single time. Only did it when the US company demanded it.
All packages, insured or not were horribly damaged in transit. Unless goods were packed such that they could survive a fall onto hard concrete from 1.5 meters, they would be damaged.
Rates were all over the place in the US, in Germany they were standardized. To this day, I've never figured out how the same size/type/weight of package sent the same way to the same address from the US could vary in cost by factors of 100s of percent.
Now, nearly everything breakable I had sent to relations in the Netherlands and then sent on from there to Munich arrived in perfect condition. Ditto the reverse direction. And so, after far too much commentary, my recommendation: Determine with whom and how you ship stuff to Europe dependent upon which country it's going to. Germany/US seems to work far better and much cheaper than US/Germany, but damage was enormously high.
Oh, and in my experience:
USPS, UPS, FedEx in that order of speed of delivery.