This article explains how to access the source code of a message in Gmail so you can view information that isn't included in the email message.
How to track where an email came from
The source code of the email shows the email header information and often the HTML code that determines how the message is displayed. This means you can see when the message was received, the server that sent it, and much more.
Open the message for which you want to see the source code.
Look at the top of the email where the subject, sender information, and time stamp are located. Next to it is the Reply icon and the three stacked dots for the menu. Select the icon with the three stacked dots to reveal the additional options.
