Story highlights State Department found only one previously unreleased email related to Benghazi -- a note from the then-U.S. ambassador to Brazil

Nearly 15,000 documents from Clinton's server recovered from the FBI were reviewed

Washington (CNN) Only one email from the batch of 14,900 new documents the FBI found from Hillary Clinton's private server directly references the Benghazi attacks -- and that was a letter of praise from an ambassador, the State Department said Wednesday.

The State Department is reviewing the large trove of documents recovered from Clinton's server and last week said that as many as 30 exchanges could be related to Benghazi. But the department told a federal court Wednesday that all but one had been previously released.

The newly published exchange is an innocuous note from former U.S. ambassador to Brazil Tom Shannon, praising then-Secretary of State Clinton on her performance at a 2013 Senate hearing on the Benghazi attacks.

"Please extend to the Secretary my congratulations for her testimony today before the Senate Foreign Relations Committee. I watched with great admiration as she dealt with a tough and personally painful issue in a fair, candid, and determined manner," Shannon wrote in the email sent January 23, 2013, to Cheryl Mills, a top Clinton aide.

State also issued parts of two other conversations that were previously released with the exception of "Pls print" instructions from Clinton. One is from Clinton thanking State workers for their work on Benghazi and another from a former advance man in the Clinton White House, Rick Jasculca, praising Clinton's performance.

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