Brew the Tea: In a small saucepan, bring 1 cup of water to a boil. Remove from heat, add the tea bags, and steep for 5 minutes. Discard the tea bags and let the concentrate cool slightly.
Make Mango Puree: While the tea is steeping, add the diced mango, honey (or sugar), and lemon juice to a blender. Blend until completely smooth.
Combine: In a large pitcher, combine the warm tea concentrate and the mango puree. Stir well until fully mixed.
Dilute and Chill: Add the remaining 3 cups of cold water to the pitcher and stir.
Serve: Fill glasses with ice, pour the mango iced tea over top, and garnish with fresh mint or a slice of mango.