But before he arrives at the White House, he will probably be forced to sign off. In addition to concerns about e-mail security, he faces the Presidential Records Act, which puts his correspondence in the official record and ultimately up for public review, and the threat of subpoenas. A decision has not been made on whether he could become the first e-mailing president, but aides said that seemed doubtful.
This is bogus. The U.S. government should have the security capabilities to make it possible for the president to have an e-mail account (for official business and personal use).
And, the POTUS should know how to use e-mail in a way that would not get him in trouble during his time in office and on the historical record.
Yes, he can.