The greeting is of different types. There are different greetings with different people. I tend to greet friends with handshakes, and hugs close friends. The greetings change accordingly with the closeness I share with the other persons.
Aware of the closeness and formality I maintain, I always considered ‘handshake’ as the most formal greeting which I tried when I met teachers in different places.
At first, I was dumbstruck when people rejected my greetings. I had a facepalm moment keeping my hand in air waiting for them to shake their hands. Neither gents nor ladies looked forward to shaking their hands with me. They used to join their hands and greet me saying, 'Namaste'.