A secure email service used by Edward Snowden is relaunching

Lavabit, an encrypted email service once used by exiled whistleblower Edward Snowden, is relaunching.

After the NSA contractor stole thousands of highly confidential documents about US spying capabilities and fled the United States in 2013, investigators went after the startup he had used as an email provider.

They demanded that founder Ladar Levison install surveillance equipment on Lavabit's servers, Levison recounted in a column for The Guardian in 2014 - and also hand over private encryption keys that could have allowed investigators to read its 410,000 users' private messages.

Rather than comply with the court order, Levison ultimately shut down his company completely.

A little under four years later, and Lavabit has been resurrected - with a range of security features to protect users' privacy from the prying eyes of the government, and Lavabit itself.

"This is the first step in a very long journey," Levison told The Intercept in an interview about the relaunch. "What we're hoping for is that by the end of this year we'll be more secure than any of the other encrypted messaging apps out there on the market."

The formal relaunch took place on Friday - Inauguration Day for Donald Trump, 45th president of the United States.

"Today is Inauguration Day in the United States, the day we enact one of our most sacred democratic traditions, the peaceful transition of power. Regardless of one's political disposition, today we acknowledge our shared values of Freedom, Justice, and Liberty as secured by our Constitution," Levison wrote in an open letter on Lavabit's website. "This is the reason why I've chosen today to relaunch Lavabit."

Right now, new users can't create accounts on Lavabit - but old users are able to reactivate their accounts. But when new users can sign up, they'll be able to decide just how security-conscious they want to be - from "trustful" to "paranoid" - and the service will handle their encryption and security accordingly.

Snowden told The Intercept that he plans to reactivate his old account, "if only to show support for their courage."