Story highlights Cambridge Analytica employees did not start working for Trump campaign until July 2016

The firm was part of the Trump campaign's three-pronged data operation

(CNN) Cambridge Analytica funder and Trump donor Rebekah Mercer received an email in August 2016 from someone she had recently met at a political event, suggesting that they create a searchable data base for Hillary Clinton emails in the public domain.

Mercer then forwarded the suggestion to several people, including Cambridge Analytica CEO Alexander Nix, asking if this is something they could do.

That is what prompted Nix's email response that he had contacted Julian Assange two months earlier asking for Clinton's emails, according to a source familiar with the Mercer and Nix email chain.

The source would not disclose the name of the person who originally emailed Mercer but did say, according to the email, they met at a Ted Cruz related event. Before supporting Trump, the Mercer family backed the Texas Republican's presidential campaign.

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