As Barack Obama began preparing to leave office, the first smartphone-toting U.S. president ordered his team to upgrade the White House’s aging technology for his successor. New computers were purchased and faster internet was installed. Not included in the modernization plans? A courier service. But that delivery method of a bygone era may be in for a comeback under Donald Trump. Despite his voracious use of Twitter, the president-elect appears to be leaning toward old tech to ensure the security of sensitive messages. “It’s very important, if you have something really important, write it out and have it delivered by...