Another first

I posted a while back about seeing an ATM filled for the first time and the rarity of seeing a billboard being changed. Today I saw a free-standing mailbox being emptied and I thought, "Have I ever seen this?" I couldn't recall a time, so I think it was another first. Sometimes when I mail things in those mailboxes, I think about not seeing them get emptied. Will my mail actually get where it is supposed to go? But it always does, so apparently they do get emptied when they say they will, even if I rarely see it happen.