Most of us using email for business will have encountered phishing emails.
These are attempts to mislead and fool both the IT email systems and human recipients of an email, typically in pursuit of fraud or to spread malware.
Google do a great job of spotting and filtering bogus emails (spam, malware, fraudulent) however a well crafted and targeted phishing email looks very much like a real email, making them harder to filter out.
If you receive an email which you believe is not from a genuine source then you can report it using a special Report phishing method in Gmail (on the web).
When viewing a message click the drop-down arrow next to Reply at the top-right of the message pane and select Report phishing. This will remove the email from your inbox and send a report to Google to help in the fight against scammers and fraudsters.
If an abusive email was sent from a Gmail account you can optionally report it via this page: