so i got a question about the postal service which has been bugging me for a while. any of you know how it works, do let me know.

suppose i mail a letter from toronto to karachi. i pay the postage here, so who pays for all the cost of the letter after it leaves canada, the route to get to pakistan, and delivery after it reaches pakistan? i doubt my postage will cover the entire cost of the journey nor will the recieving party see much of it, but they end up delivering it regardless.