In diagnosing email delivery issues it is often necessary to view the Internet Headers of the email message received. The Internet Headers can only be acquired from the email client that receives the message. This explains how to retrieve the Internet Headers from a few popular mail clients.
From Outlook, first open the email in a separate window and click the File menu option.
From the next window, click on the Properties button.
The Internet Headers appear in the box near the bottom of the Properties window.
From Yahoo, open the message in a browser window and look for the drop down under the 3 dots at the top.From the dropdown, select View Raw Message to get the Internet Headers on the next page.
From Gmail, open the message in the browser window and select the arrow for the dropdown to the right of the page. Select Show Original from the dropdown to see the Internet Headers on the next page.