Stir sugar and contents of pectin package in a bowl until well blended.
Add mango and peppers. Stir 3 minutes. Ladle jam into clean jars to fill line. Twist on lids. Let stand until thickened, about 30 minutes. Refrigerate up to 3 weeks or freeze up to 1 year.
NOTE: When cutting or seeding hot peppers, wear rubber gloves to prevent hands from being burned. Makes about 4 (8 oz) half pints.