Letters are usually sent by ordinary mail. You should go to the mailroom next to the big tree near the main building in the central area to get it yourself. Don't deliver the letter to your door. When writing the address, only write the dormitory, not the class, because if you write the class, you must get the seal of the class liaison, and you can't get it yourself. Write a dormitory building and tell the aunt who got the letter to pay attention next time and take her student ID card to get it.