Anthony Scaramucci stands by during the daily briefing at the White House in Washington, July 21, 2017. Jonathan Ernst | Reuters

"I don't officially start until the 15th Rob. But I just wanted to drop you a line to say if you ever need to pick my brains then my door is always open," Scaramucci wrote in the email. "Obviously there is still pressure on all sides, but if we remain consistent and united I don't envisage any issues we can't ride out." Trump fired Scaramucci on July 31, not even two weeks after his appointment, after the financier gave a profanity-laced interview to the New Yorker magazine that he believed was off the record. Since then, Scaramucci has returned to SkyBridge as a co-managing partner while often defending Trump and his agenda in the media. The source declined to explain the substance of Scaramucci's meetings with Goldstone. But when asked why Scaramucci interacted with Goldstone, the source said Goldstone "was helpful on the campaign." When asked to explain how Goldstone was helpful, the source said that the publicist was "just hanging around the campaign. Nothing specific." CNBC asked Scaramucci to elaborate on his interactions with Goldstone, but he declined to comment.

Scaramucci and the Trump campaign

The SkyBridge founder worked as a member of the Trump campaign's finance committee, helping it raise millions of dollars in the stunning effort that led to Trump's upset over Clinton. He had previously worked in finance roles on the failed campaigns of Wisconsin Gov. Scott Walker and former Florida Gov. Jeb Bush. Scaramucci joined the Trump team in May 2016, the month before the Trump Tower meeting. He was not a participant in the gathering, according to published lists of attendees. In a statement to CNBC on Wednesday, he denied that his email to Goldstone had anything to do with Russia.

While it's unclear what Goldstone might have done to help the Trump campaign, the source said there could be more emails between Scaramucci and the British publicist that have not been made public. Scaramucci was "hoping they released more" emails, the source said of the Senate Judiciary Committee's document dump. "The reason (he) would like to see (more) emails" is for context. It "had nothing to do with Russia," the source added. The Trump campaign did not immediately respond to CNBC's request for comment.

Getting their story straight

The panel published hundreds of emails and other pieces of evidence among the 2,500 pages of findings from its yearlong investigation into the Trump Tower meeting. Some of the documents showed Donald Trump Jr.'s attorneys scrambling to get the participants in the meeting to follow the same message once the gathering became public. One exhibit released Wednesday shows Goldstone forwarded an email from Trump Jr.'s attorney Alan Futerfas. In the email, Goldstone is asked whether he is comfortable with how a statement about the Trump Tower meeting was written. The statement, in part, read: "As the person who arranged the meeting, I can definitely state that the statements I have read by Donald Trump Jr. are 100 percent accurate. The meeting was a complete waste of time …" When Goldstone was asked during his private committee hearing whether he ever released the statement, he replied "no" and called it "ludicrous" because it seemed like "an across the board endorsement of Mr. Trump Jr."

British publicist Rob Goldstone arrives at a closed door meeting with House Intelligence Committee December 18, 2017 on Capitol Hill in Washington, DC. Getty Images

Futerfas disputes that claim. He told CNBC that Goldstone had, in fact, cleared the statement with his team. "Mr. Goldstone was advised that 'any statement should be accurate as to your very best recollection' to which Mr. Goldstone replied, 'Thanks looks good to me,'" Futerfas said. Futerfas would not provide CNBC with the email that purportedly showed Goldstone corroborating what Trump Jr.'s attorney proposed at the time. Goldstone's attorney did not return repeated requests for comment. Representatives for Senate Judiciary Chairman Chuck Grassley, R-Iowa, and ranking member Sen. Dianne Feinstein, D-Calif., also did not return calls for comment.

Having Donald Trump Jr.'s back