This is a tiny location in a strip mall near Ross and La Bonita Market. It's very busy- mostly senior clients who probably live in the area (regulars). There is usually one person at the desk (which explains the "closed for lunch" policy). There are convenient saturday hours, but it closes at 1 pm, so get here early. If you can stand waiting a bit, it's worth coming here, since there are so few in the area. (The one across UNLV is mon-friday only.)
Mailboxes are to the right as you walk in the door. There is a dropbox in front of the little outpost, if you just need to drop off something that's already posted/stamped.