Henry is working from a USDA office. He has several tasks to perform today: 1) he logs onto his USDA computer to get started; 2) he faxes a sensitive document to his supervisor using a fax machine with the appropriate clearance; 3) he confirms some appointments and project due dates and enters them into his smart phone; and 4) he calls his supervisor on his cell phone to review the document he just faxed over. Which of Henry's actions was a mistake?