In a saucepan, bring 2 cups of water to a boil. Once boiling, remove from heat and add the loose black tea or tea bags. Let steep for 5 minutes, then strain out the tea leaves or remove the tea bags.

While the tea is steeping, place the diced mango in a blender. Blend until smooth, then strain through a fine mesh sieve to remove any pulp, if desired.

In a large pitcher, combine the brewed tea, mango puree, sugar, and lime juice. Stir well until the sugar is fully dissolved.

Chill the mixture in the refrigerator for at least 1 hour.

To serve, fill glasses with ice cubes and pour the chilled mango iced tea over the ice. Garnish with fresh mint leaves if desired.