How to get IP Address using Foxpro Command

Hi
I need to know if someone sends me file via an email attachment, and if I want to know his IP address using Foxpro command when he is connected to the internet, then is it really possible to get his IP? I need to know this urgently, as I am getting sensitive emails from someone regularly, but after opening that I found it false. Before taking legal action I need to be sure about his IP Address. So can anyone please inform me the process of retrieving the IP address using Foxpro Command.
Thanks
