The postal service to and from Nepal is, at best, erratic but can occasionally be amazingly efficient. Most articles do arrive at their destination…eventually.
Having stocked up on gifts and souvenirs in Nepal, many people send them home from Kathmandu. Parcel post is not cheap or quick, but the service is reliable. Sea mail is much cheaper than airmail, but it is also much slower (packages take about 3½ months) and less reliable.
As an indication, a 2kg package to the UK/USA costs Rs 1645/2045 via airmail, or 25% less at ‘book post’ rate (a special rate for books only).
The contents of a parcel must be inspected by officials before it is wrapped. There are packers at the Kathmandu foreign post office who will wrap it for a small fee. The maximum weight for sea mail is 20kg; for airmail it’s 10kg, or 5kg for book post.
If an object is shipped out to you in Nepal, you may find that customs’ charges for clearance and collection at your end add up to more than the initial cost of sending it. Often it’s worth paying extra to take it with you on the plane in the first place.
Airmail rates for a 20g letter/postcard within Nepal are Rs 5/2; to India and surrounding countries Rs 25/20; to Europe and the UK Rs 40/30; and to the USA and Australia Rs 50/35.