These tropical burgers pair well with a porch on a sunny day.
In bowl, stir first 4 ingredients; season mango relish. In another bowl, mix beef, jerk seasoning, and garlic; season. Form into 6 patties. Grill over medium-high heat to desired doneness, about 3 minutes per side for medium. Spread mayonnaise on buns. Build burgers with buns, patties, mango relish, onion, and lettuce.