Pour condensed milk into a large mixing bowl. Add the zest of two limes. Squeeze desired amount of juice from the two limes (I used 1 1/2 limes worth of juice, because the limes were extremely juicy, but you could certainly use both) into the bowl. Add vanilla and salt, then stir.

Add coconut and flour; stir well.

Preheat oven to 325 degrees. Line a baking sheet with parchment paper. Use a small cookie dough scoop to scoop small mounds coconut mixture onto parchment paper. Bake at 325 for 25-30 minutes, or until top of macaroons become golden brown.