Actually their belts are sent in ordinary unregistered envelops (like normal letters). What i used to do to avoid the postman (woman in our area) from throwing the envelop over the gate or leaving it stuck between the gate latches, was as soon as I purchase a belt, I would inform her about an envelop coming in a couple of weeks time.
When the yellow envelop with the belt reaches, she would get off her scooter, come inside, ring the bell and hand over the envelop. A cup of tea and biscuits are immediately arranged by wifey for repaying the courtesy.
I also get other stuff like spare parts that come from abroad with India post as the delivery partner. Having an amiable postman does help a lot.