Old Navy is having another mystery sale. Check your email (or sign up for Old Navy emails if you haven't already and you receive a welcome gift of $5 off your next order). Old Navy just sent out one of their mystery coupon emails. You will receive a one-time use code in your email that will be good for 15%-50% off! I didn't get lucky this time (mine was 15%), did you? Post a comment and let me know what you scored with your coupon. If you spend over $50 use code ONSEND50 or pay just $7 for flat rate shipping on orders under $50. For a limited time you also get 10% cash back through Ebates!