Date 24/2/2013
Millions of emails fly through cyberspace daily, and as is the case for
many users, it can be useful to identify the location that the e-mail
originated from. Persistent spam and malware attachments abound.
Sometimes it is best to say, “I have had enough!” Particularly for
e-mails that include malware, this is important. By reporting these
locations, you spare others from having to deal with malicious programs
or domains. Let these users know that you know where they are and don’t
hesitate to report malicious software spammers to the appropriate
authorities.
On a nicer note, it may be useful to know the location of a prospective
client for business purposes so you may prepare a proposal significant
to their demographic. This can be a benign and useful process as well
as one to defend. The process is the same. You choose what to do with
it. This gets technical, so prepare for some work.
Here is how to take the steps for Google's mail service Gmail.

In Gmail Track any email to its Original Location by Finding the Email IP Address