Methods of communication like Flying Sword Transmission and others have long existed on the mountains of the Wangque Continent.
However, they are not widespread.
They are too expensive for Wild Cultivators and small Immortal families and not secure enough for Great Cultivators and Great Immortals.
Moreover, for the latter, sending a trusted person to deliver letters and treasures is obviously more reliable.
Thus, only a few top-notch firms on the mountains of Wangque offer these services, catering to cultivators who aren't short of spirit money and seek convenience.
Most of the young, talented Residence Students of Taiching Prefecture belong to this category and are also fond of trying out various novel things.
Therefore, Taiching Prefecture has a dedicated Post House Pavilion, where the daily inflow and outflow of letters is quite frequent.
It's a bustling place within the prefecture, with frequent interactions between the students and the Post House Managers.