Book your train ticket in advance before you arrive or depart from Milan Malpensa Airport. It's a one-way 1st Class ticket and it's valid for 4 hours. You can take any of the trains which run every 30 minutes in the next 4 hours. It can be used to/from Terminal 1 and Terminal 2 of MXP Airport. This is an E-Ticket, therefore no need to take a print out. Just show the ticket on your smartphone. You can depart or arrive from Terminal 1 or Terminal 2, the cost is the same. Coming from Milan, first is Terminal 1 and after Terminal 2 which is the last Stop of the Train.