This e-mail is for all of yours
I appreciated everything you have done for me on this trip to China, and I want you to show this e-mail to your manager.
You are a very, very good workers, I feel I have the obligation to call you again next year because your service doesn´t have words to express as good as it is.
Realy, from my heart thanks for everything, If you need something in my country (Colombia) you only have to ask me
Best regards