A letter poem, more commonly referred to as an epistolary poem, is a poetry form that follows a letter-like format. The earliest known epistolary poems date back to the early Roman poet Ovid, whose work "The Heroides" was written from the vantage of heroines of Greek and Roman mythology.
Epistolary poetry can encompass a wide range of tones and styles. It can vary from intimate to formal. It can address individuals, the world, nonexistent beings or concepts. Some, such as Langston Hughes' "Letter," begin with a traditional opening address, while others can take on a more nontraditional look and feel.