India, Oct. 28 -- A massive data breach has reportedly put millions of email users at risk, including accounts associated with Google's Gmail. Troy Hunt, an Australian security researcher who runs the breach-notification site Have I Been Pwned, claimed that the stolen trove, which has surfaced online, contains 3.5 terabytes of data.

The compromised dataset contains 183 million unique accounts and about 16.4 million addresses that have not been affected by previous breaches, reported the New York Post.

The outlet reported that users can visit HaveIBeenPwned.com to check if their credentials have been compromised. The site gives a detailed timeline of a flagged email breach.

If a user's email address is flagged, the first thing to do is ...