How to forward a message with headers in Gmail

Every email has headers. The headers contain information about the path the message took through the Internet. Email headers are normally hidden, but contain information that is very valuable when it comes to troubleshooting problems or trying to determine an email's source.

1. Open the Gmail message.
2. Click the down arrow next to Reply, at the top right of the message pane.
3. Select Show Original. The full headers will appear in a new window.
4. Click Download Original and save the text file.
5. Attach the text file in a new message.