The coupon is surely valid, but if you changed your email since you originally purchased it, it will say it's not valid so, you have to contact us via email so we can update your old orders with the new email.
Note that, for that Coupon to qualify you have to buy Zurich. We had a promotion a while ago that we gave Zurich for free if you purchased JFK+KORD together. If you obtained Zurich that way, the Coupon would not work.