In short, you can't. Origins can be spoofed, and even if they aren't, any consumer-grade email service would obfuscate the geographical origin of any email anyways.
This only works if they sent the email from their computer via an email program like Thunderbird or Outlook. If they use the web interface to send mail, it only gives the IP of the service provider.
This only works if they sent the email from their computer via an email program like Thunderbird or Outlook. If they use the web interface to send mail, it only gives the IP of the service provider.