Thousands of Hillary Clinton’s emails may be gone — but not necessarily for good.

Some of the more than 30,000 “personal” emails deleted by the former secretary of State may still be recoverable in some form, technical experts speculated to The Hill, if investigators can get their hands on her private server.

“Email is really, really hard to get rid of,” said Marcus Rogers, the director of Purdue University’s Cyber Forensics and Security Program.

“So if they’ve got the server and it hasn’t been wiped, then the probability of recovering the emails is extremely high.”

{mosads}“A lot of times if you don’t delete things properly, you can still recover them potentially after the fact,” agreed Jonathan Katz, the director of the University of Maryland’s Cybersecurity Center.

Critics pounced on Clinton’s claim on Tuesday that she had deleted roughly half of the 60,000 emails sent through her personal account and run through a private server while she was secretary of State. The rest, which were deemed to be official emails, were sent to the State Department for preservation.

Transparency advocates have bridled at the notion that Clinton and her aides alone, instead of an impartial body, decided what was considered relevant for storage by the government.

Rep. Trey Gowdy (R-S.C.), the head of the House Select Committee on Benghazi, has called on Clinton to turn the server over to a third party to make sure that anything official is preserved. 

But Clinton isn’t giving in.

“I believe I have met all of my responsibilities, and the server will remain private,” she said on Tuesday.

If investigators did get their hands on the machine, there’s reason to believe they would be able to do some digging.

Wiping drives on a server is a relatively extreme step to permanently erase all the data on those drives. It’s unclear what Clinton did to erase the thousands of emails that she says are about her daughter’s wedding, yoga routines and other personal matters, but it seems unlikely that she would wipe out the drive for good.

“That’s kind of your nuclear option,” said Rogers.

Clinton has said she did not send any classified emails through her personal account and that “robust” encryption techniques were used to safeguard the data.

“There were no security breaches,” Clinton said.

Stanford computer researcher Jonathan Mayer pushed back at the notion that Clinton used a crude email system, and said it clearly had “nontrivial security protections in place.”

But it’s unclear how well the defenses could withstand any sophisticated attacks that may have been lobbed at it.

If there was a hack, the server might contain telltale traces of a successful intrusion.

“In general we know from the corporate world that there’s a lot of instances of companies being hacked and the companies not knowing or not identifying it until well after the event,” said Katz. “It’s certainly possible that the server was hacked and they just don’t know about it yet.”