When Janie and Dylan are setting up the Christmas tree in the barn, it changes from being a real tree into a fake, decorated one in the next shot. The tree also changes in shape.
They would not use snail mail for a real-estate deal like this.
When Janie is on the phone to Charlie you can see that it's not a real phone.
It would be legal malpractice not to follow the client's demand and mail the offer for the farm.