Prepare and bake Piecrust in a 9-inch pie plate. Cool completely on a wire rack.
To prepare filling, combine nectar and next 5 ingredients (nectar through eggs) in a large saucepan, stirring with a whisk. Bring to a boil over medium heat, stirring constantly. Cook 1 minute, stirring constantly.
Remove from heat; stir in butter and 2 teaspoons rind. Spoon mango mixture into a bowl; place bowl in a large ice-filled bowl for 10 minutes or until mango mixture comes to room temperature, stirring occasionally. Remove bowl from ice; spoon mango mixture into prepared crust. Cover and chill 8 hours or until firm.
To prepare meringue, place egg whites and salt in a large bowl; beat with a mixer at high speed until soft peaks form. Combine 1/2 cup sugar and water in a saucepan; bring to a boil. Cook, without stirring, until candy thermometer registers 238°. Pour hot sugar syrup in a thin stream over egg whites, beating at high speed until stiff peaks form. Spread meringue over filling; garnish with rind, if desired.