Even though Gmails filtering system is better then other email providers, it has to continuously work on improving along with adding some common sense. If the Spam filters can’t identify emails from its own domain are legitimate, how can they identify other innumerable servers online. Like the one below I got from email@example.com into my SPAM box. We’ll still have to look at all emails with SPAM folder ( label ) .
Google wants us to Report that firstname.lastname@example.org is an email from their own server.
If our system flags a message as phishing, but you’ve validated the source from which the message originated, click the down arrow next to Reply at the top-right of the message pane, and select Report Not Phishing to let us know the message is legitimate. And if you receive a message that our phishing detection system doesn’t pick up on, click Report Phishing to send a copy of the message to the Gmail Team.
Watch this excellent educational video from Gmail: Spam, time, and you