President Obama’s high-security BlackBerry used a special process known as “whitelisting” that only allowed it to take calls and messages from pre-approved contacts, two former senior intelligence officials with knowledge of the set-up told Fox News – pointing to the detail as further proof the White House knew Hillary Clinton’s private account was used for government business.

As the administration now acknowledges, Obama and Clinton emailed each other while she was helming the State Department. If received on his BlackBerry, the “whitelisting” safeguard means Clinton and other contacts would have had to be approved as secure for data transmission – covering everything from emails to texts to phone calls. The Obama BlackBerry would have also been configured to accept the communications.

“Think of whitelisting like a bouncer in the VIP line at the party. If you are on the list you get in, if you are not, you get bounced to the pavement,” said Bob Gourley, former chief technology officer (CTO) for the DIA, and now a partner with strategic consulting and engineering firm Cognitio.

“Whitelisting happens by design. The IT professionals who whitelist devices at places like the White House only add the email addresses authorized by management. To do otherwise would be to violate policy in ways that could introduce threats to the system,” he added.

A second former intelligence official, who asked to speak on background, described the same process for the president’s BlackBerry, adding the timing is important. If clintonemail.com were “whitelisted” before March 2015, it would further undercut administration statements.

President Obama initially claimed in March 2015, when the details of Clinton’s secret server were first made public by the New York Times, that he only learned about the system from news reports, along with everyone else. Press Secretary Josh Earnest later walked that back, but maintained at the time that while Obama knew about Clinton’s email address, he was not aware of how the address and server had been set up.

While there is a difference between a private server and email address, if the president's BlackBerry were configured to accept the Clinton address, it would have been clear to those handling the request that clintonemail.com was not a government account.

Both Gourley, and the second former intelligence official said typically these request comes from the White House Chief of Staff or a deputy, and are directed to the Secret Service and the White House Communications Agency (WHCA), which is a military unit assigned to the task.

Earnest dismissed questions Wednesday about their March 2015 statements.

"The president's explanation in March of 2015 and my explanation of what the president knew in March of 2015 hasn't changed, and the truth is this is just critics of Secretary Clinton and President Obama recycling a conspiracy theory that has already been debunked," Earnest said.

Emails hacked from Clinton Campaign Chairman John Podesta’s account and posted by anti-secrecy site WikiLeaks have provided additional details about the problems Obama’s initial statements caused in March 2015.

One of Clinton's top aides urged colleagues to "clean this up" after Obama claimed he only learned of Clinton's private email system from news reports. According to one March 7, 2015 email, Cheryl Mills challenged the president’s statement to CBS News.

"We need to clean this up - he has emails from her - they do not say state.gov," Mills wrote to Podesta just before midnight.

In emails released by the State Department earlier this year, Mills also asked Lewis Lukens, who was the executive director of the State Department’s executive secretariat, about getting one of the highly secure BlackBerrys for then-Secretary Clinton.

“so I have now read up more on POTUS bb which appears not really to be a bb but a different device) is there any solution to her being able to use encrypted bb like the nsa approved one he has in the vault, and if so, how can we get her one,” she wrote. The request was never granted.

Less than a month after Clinton became secretary of state, and the personal email domain that she would use exclusively for government business was registered, Hillary Clinton's team aggressively pursued changes to existing State Department security protocols so she could use her BlackBerry in secure facilities for classified information, according to new documents released under the Freedom of Information Act.

"Anyone who has any appreciation at all of security, you don't ask a question like that," cybersecurity analyst Morgan Wright told Fox News. "It is contempt for the system, contempt for the rules that are designed to protect the exact kind of information that was exposed through this email set up."

Current and former intelligence officials grimaced when asked by Fox News about the use of wireless communications devices, such as a BlackBerry, in a SCIF (Sensitive Compartmented Information Facility) -- emphasizing its use would defeat the purpose of the secure facility, and it is standard practice to leave all electronics outside.

A former State Department employee familiar with the Clinton request emphasized security personnel at the time thought the BlackBerry was only for unclassified material, adding their concerns would have been magnified if they had known Clinton's email account also held classified material.

"When you allow devices like this into a SCIF, you can allow the bad guys to listen in," Wright added.

FBI records show that President Obama used at least one pseudonym to exchange emails with then Secretary of State Clinton. The State Department withheld eight email chains that totaled 18 messages between the president and Clinton which remain confidential under the Presidential communications privilege.

Asked if the President’s BlackBerry was configured to accept the clintonemail.com address, a spokesperson for the Secret Service referred questions to the White House Communications Agency and the White House Military Office. Fox News is attempting to follow up with both.