When I was courting (that dates me!) communications were made via the Royal Mail or the General Post Office telephone. The telephone was preferable as it was free if you knew how to "tap" the number. Letters were generally written in the evening after returning from work and deposited in the main post office (which is now a Wetherspoon's Pub) later that evening.The journey from small town in Bucks to larger town in South Devon was accomplished by the next morning - door-to-door.
Around 1pm today, Thursday, I received a letter in central Preston which had been posted in an Oxford suburb on Saturday. As it was important, a first class stamp was affixed. The stamp was not franked so I have no evidence with which to complain about the service. That's progress!