I would like to understand if an IP address on an email gives away your location to an ordinary person, or a person with some reasonable IT savvy. I was given to understand that a computer's IP address is embedded in a header somewhere in emails sent out. If I am in city X and send out an email, and I go to city Y and send out another email to the same person, would they be able to discern that my location has changed? And if yes, how? And I wonder if you wouldn't mind answering the same question if I am using my IPhone to send emails. Would it be discernible to the same person that my IP is no longer in city X, but in city Y?