You haven't encountered Postal workers in South Florida then. If you think most people in line can't speak English, it seems most postal workers can't understand it.
If you only make the occasional 1-2 trips per month to the post office, then that is nothing. But if you go regularly, why not just prepare everything at home and have them pick it up or drop it at the drop box on the side of the road? That is what I do. Whenever I come back from shooting a cruise trip or land vacation, I do all the photos here and simple print postage to stick on them and arrange a pick up from the USPS.com site. Last thing I want to do is haul in 2000 individual CD mail pieces to the post office counter.
You even save a bit more from doing it at home too.