Seller protection requires an online viewable proof of delivery.
First Class Mail International and the Priority Mail International Flat Rate Envelopes/Small Flat Rate Boxes don't have any tracking or delivery confirmation included. But, you can add a Registered Mail number at the post office and get tracking and delivery confirmation with that as well as $45 built in insurance.
Other Priority Mail Int'l and Express Mail Int'l have tracking/delivery confirmation and some built in insurance.
If your item is over $250, there is no way to guarantee a signature on delivery, although the odds are better that you will get one collected at the delivery post office's website with Express Mail Int'l.
