Originally Posted by Havplenty

on usps.com website the padded flate rate envelopes are still a flat rate price. maybe they have not changed it to "by weight" yet. they give you a receipt when you mail an international package which is your receipt of mailing. the postal service cannot track an international package once it leaves U.S. soil so you cannot purchase tracking.

first class mail is only up to 13 ounces so i am not sure what kinda swap package would be under 13 ounces unless one sends a gift card instead of items.