[Talking_Mouse]

They can find out what workstation has that IP address, and at what time the email was sent. Then who was logged onto that workstation at that time was, most probably, who sent the email.

[rwfromkansas]

But, wouldn't he need somebody from inside Reuters giving him that info?

I think the best you can do outside is pinpoint the general area it is coming from, the Reuters office...but that is about it.