Google added new alerts to Gmail this week in order to improve the security of its users. The Gmail alerts inform the users when Google can’t authenticate messages and when they contain dangerous URLs. Gmail is now alerting users whenever they receive messages that can’t be authenticated with either Sender Policy Framework(SPF) or DKIM. The alert comes in the form of a question mark instead of the sender’s profile photo, corporate logo, or avatar. Additionally, Google is alerting Web users…