Google is making an annual event out of Safer Internet Day, offering tools and incentives to help keep its users safe. Today, Mountain View is adding a couple of visual cues to Gmail to alert you to potential email risks. First, you'll notice a broken red lock icon in the corner of the compose window when responding to a source that's not encrypted. Clicking the icon will remind you to double check before passing along sensitive info. Second, if you receive and email from an unauthenticated sender, the profile image will be replaced by a question mark. Of course, not all messages that Gmail flags will be malicious, but it doesn't hurt to be cautious.