Boil 2 cups of filtered water in a saucepan over medium heat until it reaches a rolling boil. Remove from heat and pour the hot water over 2 black tea bags in a heatproof container. Steep for exactly 5 minutes to extract rich flavors without bitterness. Remove the tea bags and allow the liquid to cool slightly.

While the tea is still warm, stir in 1/4 cup of agave nectar until fully dissolved. Then, add 2 cups of cold water to the brewed tea and stir well.

Peel and dice 2 ripe mangoes, removing any fibrous parts. Place the diced mangoes in a blender and blend until completely smooth. For a silkier texture, press through a fine mesh sieve to remove fibers.

In a large pitcher, combine the cooled tea with the strained mango puree and 2 tablespoons of fresh lemon juice. Stir vigorously until well integrated.

Fill glasses with ice cubes before serving. Pour the mango iced tea over the ice and garnish each glass with a sprig of fresh mint.