This was a physical letter sent out to advertise the upcoming Gates of Oblivion story arc. A scan of the letter can be seen alongside another copy of the text.
The coin included with this letter is one of three such disks that hold some significance to the Order of the Waking Flame. The cultist I acquired it from has no further need of it, and it may assist us in the near future. Study the coin, for I believe there may be a clue to the cult's activities hidden in its etched surfaces. In due time, I will summon you. Things are about to occur and I will require a mortal's touch. Be ready.