We'll look at how to see an email header on your Gmail account.
How to Access Gmail's Email Header

1. Open your Gmail account and log in.
2. Click on the email message that you wish to see the header for.
3. Select the sender by clicking the down arrow. The brief mail travel details are displayed in an information box that pops up, as follows:

Additional information is included in the original email message.
To View the Initial Notification

1. Toggle the three-dot icon in the email's left corner. There will be a menu on the side.
2. Click on the Show Original menu item.

It will contain additional information about the original letter and postal transit.

To download the message's EML file, click Download Original. It will include the email's source's raw data.