Dear Current Postmaster,
Please make sure no inter-dimensional spam letters reach their intended recipient. You’re allowed to read through time-traveling mail to ensure that the fabric of reality isn’t severed because of a boiler room marketing operation.
Best, the Postmaster in the Future
PO Box 159 at the Brooksdale Post Office is a bit unusual. Every week, it receives letters from many different people from many different times in the future. Many times, the letters are well-wishes and advice from the loved ones of people of our time. Other times, there are dire warnings.
No one seems to know how or why these letters started coming to PO Box 159. They simply appear. The future these letters describe seems to be in constant flux; one day the year 2098 sounds like a dystopian hellscape, the next day a letter will appear describing a garden of Eden.