Google did a couple of things to celebrate yesterday’s Safer Internet Day. One of them was to reward Google Drive users who checked their accounts’ security settings with an extra 2GB of storage, the other was to introduce some new security features to Gmail.

The two new authentication features are designed to alert users when emails are potentially harmful or not fully secure. The first notification will inform you if you’re sending a message to a recipient whose email provider doesn’t support TLS encryption.

The alert comes in the form of a broken padlock in the top right corner, which will also appear if you receive an email from an account that is not encrypted. Clicking on the icon will show a pop-up, warning users that the other person uses a non-encrypted email service.

“Of course, it takes at least two people to send and receive an email, so it’s really important that other services take similar measures to protect your messages — not just Gmail,” Google said in its blog.

The second security update will inform users if they receive a message from an email account that can’t be authenticated with either Sender Policy Framework or DomainKeys Identified Mail. Gmail will mark these accounts with a question mark over their profile picture.

“If you receive a message from a big sender (like a financial institution, or a major email provider, like Google, Yahoo or Hotmail) that isn’t authenticated, this message is most likely forged and you should be careful about replying to it or opening any attachments,”Google explained.

Google did remind people that not every unauthenticated email was dangerous, but it hopes that this will help people avoid scams such as phishing.

“Not all affected email will necessarily be dangerous,” Google wrote. “But we encourage you to be extra careful about replying to, or clicking on links in messages that you’re not sure about. And with these updates, you’ll have the tools to make these kinds of decisions.”