1. In Outlook, highlight the email that you want to report as Junk or Phishing. 
  2. In the top Ribbon, you should have a Junk drop-down selection. 
  3. Choose Report as Junk or Report as Phishing
  4. The email will automatically be sent to Microsoft to improve the spam filters going forward.
Outlook 2016 Report as Junk and Report as Phishing option