Open the message, click the three horizontal dots (…) on the right for More actions, then click Report Phish on the lower part of the menu.
To add the button so that it always appears in your Outlook Web App toolbar:
- Click on Settings , then click View all Outlook settings at the bottom of the drop down menu.
- Click Customize actions.
- Under Message surface, click Report Phish and then Save.
- Close out of the Settings window.