Because some of them will publish those emails. (Warning for profanity)
On Sunday morning, BuzzFeed correspondent Michael Hastings emailed Philippe Reines, Hillary Clinton's longtime aide and personal spokesman at the State Department, asking a series of pointed questions about State's handling of the Benghazi fiasco, and Reines' over-the-top attack on CNN. The emails quickly got personal, with Reines calling Hastings an "unmitigated asshole" before an exchange of harsh words on both sides.
The email chain concluded with Reines writing that Hastings should "Fuck Off" and "Have a nice life."