Hillary Clinton joked about Chinese hackers in a newly released email from her time as secretary of State.

In a 2011 exchange found among the 4,000 emails revealed by the State Department on Wednesday, Clinton wondered why she didn’t have a Gmail address for staffer Nora Toiv.

{mosads}“So how did that happen,” Clinton wrote. “Must be the Chinese!”

The release comes as critics continue to question whether Clinton’s private servers, used during her time in office with the State Department, were vulnerable to hackers.

Many have suggested that the insecure email account would have been an attractive target for foreign intelligence agents.

GOP presidential candidate and former Hewlett-Packard CEO Carly Fiorina has insisted that the private server was likely compromised.

“Hillary Clinton, of course, doesn’t understand that technology well enough to know that her sever has most assuredly been hacked, because Secret Service agents can’t protect it from being hacked,” she said in August.

The FBI is investigating whether the server was compromised during Clinton’s tenure at the State Department, but Clinton, the front-runner for the Democratic nod in 2016, has not been being accused of any wrongdoing.

Earlier this year, the Office of Personnel Management revealed that it had been the victim of a massive hack that resulted in the theft of 21.5 million former and current federal employees’ personal data.

The hack is widely believed to have originated in Beijing.