This is a great question about the Choices and Consequences world - what's the postal system like?
The answer is that it's probably a bit of a patchwork! Very locally, people will just drop messages off by hand, or send a member of their family with a letter/parcel. Businesses will have dedicated messenger/delivery staff, but there are also delivery services that serve several businesses.
For more long distance deliveries, most railway stations will act as a form of post office. Someone will take their parcel/letter to the station, make a payment, and the post is put on the train to its destination. Once it arrives, the destination station will have a delivery service for the smaller items, along with a messenger service to tell people to come and collect larger items.
Those who don’t live close enough to the station to have post delivered have to visit the station every now and then to pick up whatever is waiting there for them.
In a similar way, people can take a parcel/letter to the Settler area in the nearest town, or to any Trader caravan they come across, pay what they ask, and it will be transported to its destination by the next Trader caravan heading that way. Trader caravans cross paths with each other fairly frequently, so the parcel/letter may be passed on to another caravan several times on its journey. Trader post may be slower than rail post (and probably cheaper too) but it does get to the more remote places that don’t have railway access.
Here's an extract from Thread of Hope, the second book in the series, where Perry's mother, Mary, gets a letter from him.
Mary treasured the letters that arrived from Perry, her firstborn. When one arrived, she separated it from any other post and put it in her pocket to read later, privately. She considered them her own personal treat; she would clear the most essential chores then make a cup of tea and sit down alone to read the letter, before sharing it with anyone else, even her husband, Michael. Ted, who brought the post out to the farm, knew a little of this. If there was a letter with Perry’s handwriting on the address he would make sure he put their farm as early as possible on his circuit so Mary had the letter in time for her mid-morning cup of tea.
Perry was a conscientious and frequent letter writer and Mary wrote back quickly. Ted smiled as he handed a new letter over. “One from your lad, here,” he said and, as usual, Mary tucked it away in her pocket for later.
She was in the middle of baking a cake, and it was laundry day so it was after lunch before she found a private moment to sit down and read her letter. Her normal practice was to read it once quickly, to get the gist of any news, and then again more slowly, probably more than once, luxuriating in each word and sentence. Today she had barely skimmed the first page before she was out of her seat, running across the yard, waving the letter, and calling for her husband.
To get your copy of Thread of Hope and find out what happened next, click the button below.