For city names, directionals should be spelled out. Include a Return Address Include your return business address in the upper left corner on the front of the envelope.
The bottom line with this component is to make sure each is included.
The street or box number sits on the next line with the city, state and zip code following. Note that the physical address might not be the same as the mailing address. Include the apartment identifier at the end of the street address. If only one addressee is available, business or person, it sits on the first line.
Write the name of the intended recipient in the middle of the envelope.