The telepost came about as a means of communicating with my players as they traveled about the Wastes, a harsh, inhospitable place not too fond of things like telegraph wires. The very first batch of players to travel the wastelands included a postman. This postman was a 150 point character, who drove an armored car (military, not bank). This choice of profession for a 150 point character made, quite honestly, perfect sense. So how do towns in someplace so inhospitable get news and packages around?
Water provides stability to the region around it, condensing out some of the mana and limiting the rampant weirdness. But what might be an hour or two by direct route may be days by rivers and water travel, depending on the terrain. If you just want to get a quick message out, how do you do it? The telepost. Essentially functioning as a rudimentary email system, those with an account can request their mail from any telepost office, and any messages they may have will be printed at the location of their current check-in, even in the TL 5+1 Wastelands.
The telepost continues to be a great utility even outside of the Wastes, as the various countries that rim the Wastelands tend to be 6+1 in tech level. Telephones are common, but the telepost infrastructure is more robust without the quantity of random monster attacks and other such weirdness to deal with. Post offices and libraries are often built along a common wall, which houses the telepost's processor unit. Librarians may be able to assist researchers in their quests for knowledge using an incredibly rudimentary internet-like system. Telepost offices in more advanced areas can include such conveniences as pictures in their messages.