To add a button in Outlook to display full mail headers follow the steps below:
- Click on the File tab and select Options
- Click Customize Ribbon
- Under “Choose commands from:”, select Commands Not in Ribbon from the drop down menu
- Select Message Options… from the list
- From the List in the right, select the Home (Mail) tab and click New Group
- Click Add >> and the Message Options will be added to the group that was just created.
- To change the name of the New Group that you created, highlight the New Group (Custom) and click Rename. Type Mail Header in Display name:
To view the mail header information, select Message Options. The internet header information is displayed under Delivery options.