Just dropped in here to mail a couple letters, thinking they might go out quicker at a post office. The Summerlin Post Office seems to cover a large area in greater Las Vegas. Retail activities might not be their highest priority as there was a line inside of about fifty people. Many had packages to mail . This was Monday afternoon at 4:45 PM. I did not see anyone using the kiosk to mail their package. That's often the fastest way if the mailing is straight forward. The manager should get out of her office to show customers how easy it is to use a kiosk and to answer questions.
Maybe try another time? Learn how to so most prep at home or office with your computer or office. Then finish up in a few minutes at a kiosk,, if even necessary.