In 2005, Tsering Chopa gave up herding and became the first mailman of his hometown. Before him, the nomads seldom sent or received mail, remaining essentially disconnected from the outside world. The area was not covered by telecommunication networks until recent years.

In nearly two decades since his first mission, he has delivered over a million newspapers, more than 20,000 letters and 10,000-plus parcels in Pumachangthang, and has never been accused of failing or mixing up mail.

"The key to my success is patience. I carefully check every address at least a few times before sorting them village-wise into different bags. The routine ensures a fail-safe delivery system," says Tsering Chopa, 36.

Between July and August every year, students of the township wait for their admission letters from various academic institutions. It is understandably the busiest time for him.

He recalls a particular incident when he had to deliver mail from the medical school of Sichuan University to the township's Sharso village.

The family had moved, and he had to quiz neighbors several times to find the new address. It was summer and the usual road to the village was blocked because of rain. He trekked for more than 20 km, scaled 6,000 meters and grappled with shortness of breath to finally deliver the letter.

"When the weather is fine, it takes me three hours to get there. That day, it took me more than seven hours. I don't mind the hardships because it is not easy for students from remote villages to get college admission. It was my duty to deliver the mail on time," he says.

After handing over the admission letter to the family, he had to stay overnight in the village before he could return to his post and begin another grueling day.