I lived in the UK in the '90s, and at least back then, they still had twice-daily delivery. Even more impressive, in many cases you'd get same-day delivery of normal mail to addresses at the other end of the country.

One very memorable experience I had was sending a check in the mail to London, from Edinburgh, in the morning, and then receiving in return the ordered merchandise in the evening of the same day!!

[Those two cities are very major destinations and so mail between them is presumably well-optimized, but I was pretty flabbergasted that this was possible...]

I have heard—though I frustratingly can't find a reference anymore—that even earlier (like 19th or 18th century earlier) mail was delivered frequently enough in a given day that you could receive a letter in the morning, send a reply by mid-day, and get another reply back in the evening.

Incredible connectivity!

actually, i have found that this is still possible within new york, if you drop the letter in the mail early enough and the recipient happens to get their delivery later in the day.

next-day delivery within nyc is pretty much de rigueur.

Oh, so it's just like America.