No, it’s not “going postal”, it’s a board game from Matt Kaminski, son of a real, live, retired letter carrier.

Other than that the board is modular, the game’s official site doesn’t say much. The source says more:

The object of the game is to optimize the delivery path and be the first to finish. The game board is printed on both sides, and each side is made up of 16 5-by-5 inch neighborhoods named after towns and cities across the United States. Average playing time: 90 minutes.

Chance cards include obstacles, incidents, and transportation. Players who draw a bicycle card, for example, improve their productivity; but another card can bring the obstacle of an angry dog into the game. There are also cards that add dangers, like falling ice – but any player holding a previously drawn helmet card would be immune.

Players can also accumulate cards that can be used to help or sabotage an opponent, so as the game comes to a close, a card can be used to upset a delivery.

(source)