New York (CNN) The release of hacked emails helped derail Hillary Clinton's 2016 presidential bid. But most 2020 Democratic presidential primary candidates have not taken a basic step in securing their email systems, according to a new analysis by the security advocacy group Global Cyber Alliance conducted in mid-March.

first ran the analysis last week. Only four of the then-14 Democratic candidates' websites were using any form of a security protocol that helps ensure emails sent from campaign addresses are genuinely from the campaign when Global Cyber Alliance first ran the analysis last week

The protocol -- Domain-based Message Authentication, Reporting and Conformance (DMARC) -- verifies that emails are from the websites they claim to be from. Records of whether a website owner is using the protocol are publicly available.

According to the analysis, only the campaigns of Sen. Elizabeth Warren of Massachusetts, Sen. Kirsten Gillibrand of New York, former Colorado Gov. John Hickenlooper and spiritual author Marianne Williamson had any form of the security feature implemented.

The campaigns of Sen. Cory Booker of New Jersey, Rep. John Delaney of Maryland and Rep. Tulsi Gabbard of Hawaii implemented some form of the security feature soon after CNN asked them about it.

Read More