The features are designed to alert users when an email is potentially unsafe or not fully secure.
Starting today, Gmail messages sent or received from email providers that don't support TLS encryption will be flagged with a small unlocked padlock icon. The same goes when the sender's domain can not be authenticated.
A click on the padlock icon brings up a dialog box warning users that the other party uses an email service that does not support encryption:
Gmail said last year that it planned to warn users of unencrypted connections, so today's announcement is really a fulfillment of that promise. The company hopes the effort will convince other email providers to bolster encryption and security for their own users, and ultimately for those using Gmail.
Gmail already uses HTTPS to encrypt a user's connection between their browser and the server, but beyond that users have very little control over security as their messages traverse the internet.
In addition to the encryption warnings, Gmail will also flag unverified email contacts by showing a question mark in place of a profile picture. Unauthenticated emails aren't always dangerous or untrustworthy, but Google says the feature is designed to remind users to exercise caution when transmitting information.
And as a little celebratory bonus, Google said today that it is gifting users 2GB of addition storage for Google Drive at no cost, so long as they complete the new security checkup on their Google account.