U.S. immigration officials issued a blunt warning in an unprecedented mass email to people living in the country under specific immigration protections: “It is time for you to leave the United States.”

filed under “Notice of Termination of Parole,” the message warned: “If you do not depart the United States immediately you will be subject to potential law enforcement actions that will result in your removal from the United States — unless you have otherwise obtained a lawful basis to remain here.” In addition, “any benefits you receive in the United States connected with your parole — such as work authorisation — will also terminate.”

“Do not attempt to remain in the United States — the federal government will find you,” reads the email, which NBC News reviewed.

The communication from the Department of Homeland Security was intended for the millions of people in the United States who had fled upheaval in Venezuela, Haiti, Cuba, and Nicaragua.

However, in the days following the email’s distribution, shocking reports surfaced indicating that U.S. citizens in Massachusetts, Arizona, and Connecticut all received notices.

Nicole Micheroni, a Boston-based immigration attorney and US citizen, said she received the letter last week.

“At first I thought it was for a client, and then I kind of laughed about it a little bit, and then I was a little concerned,” she told me. “It was a range of emotions that happened pretty quickly.”

A senior DHS official stated that Customs and Border Protection was “monitoring communications and will address any issues on a case-by-case basis.”

“If a non-personal email — such as an American citizen contact — was provided by the alien, notices may have been sent to unintended recipients,” said the government official.

Micheroni and other immigration experts concur that U.S. citizens who receive the email have no genuine reason to fear deportation.

“This email was specifically addressed to people that entered the United States on parole, and parole means that the United States has agreed to let you into the United States and you don’t otherwise have a visa or a reason to be here,” according to Micheroni. “So, if you’re a U.S. citizen, you shouldn’t be entering the United States on parole.”

Nonetheless, experts warn that U.S. citizens should take precautions to protect themselves in the unusual event that they are approached by immigration authorities who question their status.

Kristen Harris, an immigration attorney in Chicago, encouraged U.S. citizens who receive the notification to contact an immigration attorney immediately.

“There is certainly no legal effect under current statute or regulation for a citizen to be ‘parole terminated’ given that especially a U.S. citizen would never, ever have been paroled in his or her life,” she said. “On the other hand, given how … fluid the current administration’s interpretation is of existing law, I think checking in with private immigration council would actually be advisable.”