Email Investigation

Based purely on the forwarded email, there is no way to check the original senders headers for potential leaks of IP. While it is unlikely that they would leak this in the email message header, there if they were to use certain email clients, there is a small chance that it would embed the IP.

If they actually used a VPN or routed it through a onion router, this would be useful so there is a very small chance that this would lead to anything. However, if you do want me to check I would need the original recipient of the email to get the raw source of the email which I would then be able to inspect.