The Dead Island 2 Mailman keys are needed when you find a special delivery crate and trigger the Lost and Found mission My Mailman was a Zombie. To start the mission and open the crate you'll need to pick up the Signature Required note to the left of the box, which will begin this side quest to find one of the Dead Island 2 keys.
I'll guide you through this mission, which rewards you with a unique Dead Island 2 weapon, a rare rifle that buffs damage when you string together hits quickly. It's a useful weapon to get early, so let me explain how to get the Dead Island 2 Mailman keys, and finish the My Mailman was a Zombie side mission.
