School post office. Inquired in official website, harbin university of science and technology, I learned that the postcards of Rongcheng Campus of Harbin University of Science and Technology were mailed in the school post office. Harbin university of science and technology, located in Harbin, is a university jointly established by the People's Government of Heilongjiang Province and the National Bureau of Science, Technology and Industry for National Defense, and was selected as one of the "Basic Capacity Building Project in the Midwest" and the "Key Characteristic Discipline Project".