The email headers can be used to look into details about an email message source. It is also helpful when reporting phishing emails. You can view full message headers in Microsoft Outlook 2019 and 2016 following the below steps.
Select message the message you wish to view the headers for and double-click the email message to display it in its own full window. You can also click the message once and select open, to open the email.
Select “File” > “Properties“.
The Properties window is displayed. Select view the message header in the “Internet headers” field at the bottom of the window. You can then copy the headers in plain text to view message details or submit them to a header analyzer.