例如

Dear Ms. Gupta,

It's our great pleasure to announce that Jan. 19th is the 3rd anniversary of the founding of our corporation. We have a small party as follows: 7:00p.m.,Jan. 19th, Room No.123, Kunlun Hotel. At this moment, we would like to express our sincere gratitude to our clients for both courtesy and support over the past three years. Please confirm if you plant to attend.

Yours Sincerely,

Lewis