It's meant to help you decide whether you really want to open an email and click on any attachments or links inside. Those are tasks many of us do countless times each day, but they also put us at risk of downloading bad stuff onto our computers or giving someone untrustworthy our login information.
Gmail already features many warning messages, but the new alerts detailed Wednesday will help in two specific situations. They'll tell you if you get an email with a link to a website known for hosting malicious software, or if Gmail can't authenticate that the email sender is who they say they are.
The warning doesn't mean the emails are definitely sent by bad guys trying to own your computer, Google said.
"But we encourage you to be extra careful about replying to, or clicking on links in messages that you're not sure about," the company added. "With these updates, you'll have the tools to make these kinds of decisions."
This article originally appeared on CNET.com.