Copy the university admissions office address onto the middle of the envelope. Make sure you leave enough space for the sender’s address and the stamp.Write the recommendation’s campus address in the upper left-hand corner. This is the return address. If the post office can’t find your recipient, they will return your recommendation letter to the recommended at this address.
Finally, write what the letter is in reference to in the bottom left-hand corner. This will probably be something like “Re:” plus your name, the words “reference letter” and, if applicable, the particular program to which you’re applying. Place each of these on a separate line.