JFK-MAD-LIS Customs/Immigration?
I am flying JFK-MAD-LIS (same routing on return). Where will I go through customs/immigrations? Will it be in MAD before continuing onto LIS? Also, on our return, will I go through security again in MAD before boarding our flight to JFK (LIS-MAD-JFK)? Asking the second question in case we pick up any bottles in the Duty Free at LIS.