|Quoting Oly720man (Reply 2):|
As far as the USPS is concerned, you can thank FedEx
Airmail, Global Priority, Global Express, and Global Express Guaranteed Mail are offered to ship mail and packages to almost every country and territory on the globe. Ironically, much of this service is provided by FedEx. 
From the USPS Wiki page
|Quoting Jorge1812 (Reply 3):|
In Germany LH has a big night hub for air mail at FRA where they put the mail between the seats of the normal pax planes.