Hillary Clinton's use of a private email server during her time as US Secretary of State is the problem that will not go away, even after the release of another 7,000 pages of messages early yesterday.
The dump is the third and largest since the former First Lady handed over the work-related emails to the State Department after wiping the server clean. Among them were 125 emails retrospectively deemed classified.
The latest batch runs from the mundane - telling Ms Clinton that her new iPad had arrived - to gossipy, including withering assessments of the British government by Sidney Blumenthal, an unofficial adviser. The email controversy has overshadowed the early weeks of her run for the White House and has repeatedly been seized on by her critics as evidence that she has secrets to hide.
She has always defended her use of a "homebrew server", rather than the State Department's own system, saying it limited the number of electronic devices she had to carry.
However, her opponents say the server meant she could avoid political scrutiny of her time at the State Department.
And they have accused her of putting national security at risk by sending and receiving classified information from an unauthorised network . Republicans, including Donald Trump, have even described her behaviour as criminal.
Mark Toner, State Department spokesman, said a review had found no evidence that any of the emails was marked "classified" or "top secret" when they were on the server.
But Ms Clinton's position has not been helped by a number of stumbling performances at news conferences. And party insiders have expressed unease at the way she has tried to make light of the issue.
"You may have seen that I recently launched a Snapchat account," she said last month. "I love it. I love it. Those messages disappear all by themselves."
Despite the questions, she remains the clear frontrunner to be named the 2016 Democratic contender for the White House, although pundits say the scandal has dented public trust in her. (© Daily Telegraph, London)