Fascinating in more than one way: I don’t think I’ve ever seen mail delivered on the same day within the same city even when my place of residence had a well-functioning postal service by modern standards. (What I have seen in a particularly egregious case, though, is letters reliably taking a month to traverse a distance that takes me half an hour on foot.)
I've been told that it was once common in the UK to be able to send an early morning letter and have a reply in your letter box by afternoon. Now, I have Post Office workers graffitiing envelopes and changing the type of postage I just paid for once I've left the Post Office, letters going missing regularly, a couple of stamps costs £10, and first class can take a week. It's now got so bad that we hand delivered cards over Christmas.
Absolutely pitiful.