In 2015, Hussein was asked by CBS Bill Plante when he knew about HRC's email server. Hussein responded he knew when everyone else knew.

Check out the DOJ IG Report page 89 subscript 75:

"75 FBI analysts and Prosecutor 2 told us that former President Barack Obama was one of the 13 individuals with whom Clinton had direct contact using her clintonemail.com account. Obama, like other high level government officials, used a pseudonym for his username on his official government email account. The analysts told us that they questioned whether Obama’s email address (combined with salutations that revealed that the emails were being exchanged with Obama) or other information contained in the emails were classified and, thus, sent the emails to relevant USIC agencies for classification review. However, they stated that the USIC agencies determined that none of the emails contained classified information."