When you receive a parcel or letter from overseas does the Royal mail actually recieve any of the carriage cost or does the postal office from where the mail originated keep all of the charge. Or do various postal services have a reciprocal agreement where they take a proportion of the charge. Any web site links that explain this in detail would be appreciated.
The Universal Postal Union (UPU), to which practically every country in the world belongs, acts as a clearing house for the payment of international postal accounts. A broad description of the system is contained in the following UPU web-page, and there may be more detail elsewhere on the UPU site - http://www.upu.int/payment_compensation/en/index.html