A cruel new email phishing scam preys on visa holders with the phony promise of a green card in return for cash, FoxNews.com has learned.

The emails, under an official-looking U.S. State Department letterhead, tell recipients they are among 50,000 winners drawn at random from more than 12 million entries in the Diversity Immigrant Visa Program, known more commonly as the green card lottery. But the elaborate emails are just a scheme to bilk money from recipients, authorities confirmed.

“We always advise people that if it looks too good to be true, it probably is,” a spokeswoman for the FBI told FoxNews.com. “We have received complaints about this particular scam that claims to be from the U.S. government.  If someone receives these emails unsolicited, they should be treated with a healthy amount of skepticism.”

Ian Jopson, an Australian citizen living in the U.S. with a work visa, received one such email as recently as Monday and figured out quickly that it was a sham.

“The header said, ‘Congratulations, you’ve won!’ I was overwhelmed because I’ve been in the [green card] lottery for years,” said Jopson. For a fleeting moment, he thought it was legitimate. Then he saw a request for nearly $900 in "processing fees," to be sent to an "embassy representative" in London through Western Union.

“It was a red flag," said Jopson, a web designer for FoxNews.com. "It’s general knowledge that Western Union is used for these things."

Another signal that something was amiss was a request that after payment, he send a confirmation message of the transfer to the email address, “lottery[at]usa-green-card-dv-lottery.com.”An email from a U.S. government agency would likely end in ".gov."

Jason Stern, a New York-based attorney who specializes in Internet issues, told FoxNews.com the scam is similar in many ways to the most famous cyber hoax of all.

"The green card lottery scam is really no more sophisticated than your garden-variety Nigerian Bank email phishing scam, except that it specifically targets immigrants -- who are particularly vulnerable to a message bearing the official looking seal of the US Department of State," Stern said.

A spokesman for the State Department told FoxNews.com the scam has been making the rounds, prompting the agency to stop sending emails out for the visa lottery altogether. The spokesman said that the government only asks for fees when applicants first apply for visas.

“You actually have to log onto the system to check the status," the spokesman said. "We do this specifically to prevent the issue of fraud.”

Perry Chiaramonte is a reporter for FoxNews.com. Follow him on Twitter at @perrych