Hillary Clinton, former U.S. secretary of state, speaks during a news conference at the United Nations (UN) in New York, U.S., on Tuesday, March 10, 2015. (Victor J. Blue/Bloomberg)

HILLARY RODHAM Clinton offered a soupcon of regret at a news conference Tuesday for having used private e-mail exclusively during her nearly four years as secretary of state. “Looking back, it would’ve been better” if she had not used a private e-mail account for official business, she conceded. Ms. Clinton said she decided to do so for “convenience” because “I thought it would be easier to carry just one device for my work and for my personal e-mails instead of two.”

Ms. Clinton noted that it is a “government employee’s responsibility to determine what’s personal and what’s work-related.” In general, this has been true; if a State Department official writes a personal note to a family member from a work e-mail address, that official can decide to withhold it from government archives. Each official has a responsibility to preserve federal records — messages and documents about policies and decisions. The methods of preservation have differed over time and among agencies; some still use paper printouts, and others have software options for preserving a record or e-mail. Government agencies are required to move to electronic preservation of e-mail records by the end of 2016.

What Ms. Clinton did not mention was that the Obama administration had clearly directed officials to use government e-mail networks for official business. She departed from this for “convenience.” Did she know about the policy? Did others know of her exclusive use of private e-mail? Did anyone raise an objection?

By Ms. Clinton’s account Tuesday, the sorting of more than 60,000 e-mail messages from her time at the State Department — to separate the personal and the work-related — was carried out entirely by her and her lawyer. She claims that all the work messages have been turned over to the department, but there is no way to check. She disclosed Tuesday that the remainder, the personal e-mails, were deleted. Why did she not provide the work-related e-mails when she left the department? Had she used government e-mail in the first place, it is possible that the messages would have been preserved there, and there might have been fewer doubts today.

Ms. Clinton also confirmed that she used a mail server at her home in New York, which was also for former president Bill Clinton, “on property guarded by the Secret Service” — as if the primary risk was not cybertheft but rather burglars sneaking in to steal floppy disks. Ms. Clinton said she did not discuss classified material in e-mail, but surely her days and messages were taken up with “sensitive but unclassified” matters that would be of interest to snoopers. She didn’t address that security issue, nor did she say anything about whether the State Department had security concerns about her private arrangement.

In the end, it is clear Ms. Clinton was acting in a gray zone, one created in part by the rapid pace of technological change. But it is also apparent that her decisions on her e-mail were based on what was best for her — what was “convenient”— and not so much for the public trust.