Write an email (100-120 words) to your foreign friend and tell him/ her

Write an email (100-120 words) to your foreign friend and tell him/ her about one & typical traditional custom in Vietnam.
You should base on the suggestions below:
- What is it?
- How popular is it in Vietnam?
- When do people apply it?
- What do people do?
- What is its meaning in terms of the Vietnamese’ culture and life.
- What do you think about it?