Office 365, Email, Exchange, How do I view mail headers?
How can I get Header information in Microsoft Exchange?
To access Internet Mail Header information for an email:
- Open a browser.
- Log in to the Outlook Web App at https://outlook.office365.com.
- Locate the message for which you want information.
- Click the More actions (...) button next to the reply and forward buttons, then select View > View message details.
- The Message details box contains the Internet Mail Headers information.