One hundred and four emails written by Hillary Clinton on a private server during the time she served as secretary of state have been called 'classified' by the government.

The new data is the first documentation of Clinton placing 'top secret' information in insecure emails during her time with the Obama Administration.

The findings by the Washington Post could make it harder for Clinton to argue she never put classified information at risk.

In most of the emails authored by Clinton, she is responding to aides with brief reactions, although she does initiate the conversation in some cases.

Hillary Clinton (pictured) authored 104 classified emails, an examination from the Washington Post has found

But Clinton isn't the only person guilty of using a non-secure email system. The analysis shows the use of these types of servers was widespread throughout the department and government.

Clinton's publicly released emails includes classified correspondence written by nearly 300 other people related to the government, The Post found.

Some senders had no U.S. security clearance along with longtime diplomats, top administration officials and foreigners.

In those cases Clinton was not the one to initiate the email or even be involved in the email correspondence, but rather was forwarded the chain by an aide.

Day-to-day government accounts with less secure servers were used by other federal employees.

Many of the 2,093 chains of Clinton's email correspondence that the State Department and the 52,000 pages of emails have significant redaction.

After examining the emails, it has been determined either the emails were 'overclassified' or sensitive information is being mishandled throughout the government.

It is also possible a combination of both things is happening.

Clinton spokesman Brian Fallon said he classification status was determined after-the-fact 'for the purposes of preparing these emails for release publicly'.

It is now thought many of the emails have been 'overclassified' after-the-fact and were not deemed classified at the time they were sent or received

'It does not mean the material was classified when it was sent or received,' he said.

The real question is if any classified information was in the emails at the time Clinton sent them.

Initially, Clinton told reporters, 'I did not email any classified material to anyone on my email.'

Then she has said that she didn't receive emails 'marked classified'.

Government rules require senders of classified information to properly mark it.

The inspector general for the intelligence community has said that some of Clinton's correspondence contained classified material when it was sent even if it was not labeled, according to the Washington Post.

Spokesman John Kirby told the Post the department’s reviewers 'focused on whether information needs to be classified today prior to documents being publicly released'.

State officials have not given the information a timeline of when it was classified.

Clinton attributes the controversy to infighting among government agencies.

Most of the emails under scrutiny, the ones authored by Clinton are short - only a sentence or two at most.

Clinton's most frequent correspondence was with top aide top aide Jacob Sullivan. He wrote 215 emails.

Clinton's private server was at risk of a breech because it did not have typical government safeguards

Many diplomats involved in the correspondences have said in interviews they were puzzled upon learning their emails had been deemed 'classified'.

They also said they never stripped classified markings from documents to send them through regular email, as Republicans have alleged, The Post reported.

Numerous emails are marked 'Sensitive but Unclassified'.

One ambassador said an email of his, now marked classified, was about a book he was having published.

Another said he would put the 'gist' of something in an email and if it needed to be discussed in detail he would 'arrange a meeting'.