One possible version：
Dear Alice,
I’m very happy to know that you’ll travel to Shanghai. As you know, Expo 2010 will be held in Shanghai, China and last from May 1 to October 31. The expo will focus on the theme “Better City, Better Life”. It is hoped that the expo will attract about 200 nations and international organizations as well as 70 million visitors from both at home and abroad. Moreover, it is expected that China will present a most successful, splendid and unforgettable expo to the world. The expo will help to create an eco-friendly society and keep up the sustainable development of the living environment.
Looking forward to meeting you as soon as possible.
Yours
Li Hua
略