Useful. Official website of Nanjing University of Aeronautics and Astronautics inquired that the correspondence course is a formal diploma, and the gold content is not too high. Some enterprises also recognize this degree in qualification examination, postgraduate entrance examination and professional title evaluation, so the correspondence undergraduate course of Nanjing University of Aeronautics and Astronautics is useful. Correspondence is a learning form of adult higher education and belongs to a learning level of higher education. Teachers are mainly sent to correspondence stations to organize face-to-face lectures and examinations in winter and summer vacations or national legal holidays according to the teaching plans of various majors.