The Electronic Delivery Confirmation program, also known as E-DELCON, allows participating countries to update USPS tracking for packages that are shipped internationally. In most cases, this results in door-to-door tracking... although some countries may not update the tracking as reliably, even though the packages are still en route for delivery.
List of Countries with E-DELCON tracking, updated October 2022
Australia
Belarus
Belgium
Canada
Croatia
Cyprus
Denmark
Estonia
Finland
France
Georgia, Republic of
Germany
Gibraltar
Greece
Hong Kong
Iceland
India
Indonesia
Ireland
Israel
Italy
Japan
Korea, Republic of (South Korea)
Lebanon
Lithuania
Luxembourg
Malaysia
Malta
Netherlands
New Zealand
Poland
Portugal
Romania
Singapore
Slovakia
Sweden
Switzerland
Thailand
Turkey
United Kingdom of Great Britain and Northern Ireland