Gmail warn users about messages from unauthenticated senders

Recently Google is rolling out a new security feature for Gmail, targeted at making email communication safer and better. Gmail users on web and Android will start receiving security warnings if they get email messages that can't be authenticated
also, security warnings will also be issued to users who may be visiting harmful websites Gmail will alert users if a message sent cannot be authenticated with Sender Policy Framework (SPF) or DKIM. As it was stated users will see a question mark in place of the sender's profile photo.
The emails that contain links to (suspected) malware and phishing sites will not load immediately in the browser. Gmail will issue a warning for such links first, before allowing the user to navigate to the link. The search giant said that these warnings are an extension of its Safe Browsing protection feature that was rolled out in March.
The security feature will be available for Gmail users on both Web and Android.
Back in February, Gmail introduced the 'Gmailify' feature for non-Gmail users. This feature gives access to access Yahoo, Hotmail and Outlook.com, directly from the Gmail's Android app.
Users can benefit from various Gmail features such as inbox organization, spam protection, Google Now cards and others. In order to use 'Gmailify,' users need to manually switch it on by linking their non-Gmail account to the Gmail app. Then just need to open the new version of Gmail app and sign in with their non-Gmail account.