In a large saucepan, add peaches, 2 cups water, 2 cups sugar and lemon zest if using.
Bring to a light simmer and simmer covered until peaches are soft and the peach skins has lost it's dark peachy color, about 15-20 minutes.
With a potato masher, mash the peaches to release more of the juice and continue simmering for about 10 more minutes.
Strain the peach mixture through a mesh strainer and discard the solids. (You'll have about 3 to 3 1/2 cups of peach syrup) Set aside.
Boil 3 cups of water.
Place tea bags in water and let them steep for about 10-15 minutes and then discard tea bags.
Add tea to a large pitcher, stir in the peach syrup, gradually add in water a cup at a time. (Be sure to taste the mixture as you increase the water until you find your perfect sweetness preference.)
If you find that your tea is not sweet enough add in 1/2 to 3/4 cup of sugar. If it's too sweet increase the water(please note the sweetness will increase as it sits in the fridge)
Refrigerate until cold.
Stir before serving and pour over ice to serve.
Garnish with mint and fresh peach slices if desired.