Aspect Ratio (length divided by height) does not fall between 1 to 1.3 and 1 to 2.5 inclusive.
Postcards: 3.5"x5" to 4.25"x6"
Letters: Max size: 11.5"x6.125"
If you get mail for someone other than the occupants of your room, place it in the Misdelivered/Missent mail slot (located next to the Outgoing Mail slot). DO NOT throw away misdelivered mail. It may be important to someone, and tampering with mail that does not belong to you is a Federal offense, punishable by law.
If you have a permanent address change, you can pick up a Change of Address Form at the Mail & Package Services Center. Change of address cards must be submitted to Mail & Package Services before mail is forwarded.
If you are trying to send mail to a Residence Hall Student, here's an example of how to address the envelope.