You get an email from a person with whom you have never interacted before and therefore, before you reply to that message, you would like to know something more about him or her. How do you do this without directly asking the other person?

Web search engines are obviously the most popular place for performing reverse email lookups but if the person you’re trying to research doesn’t have a website or has never interacted with his email address on public forums before, Google will probably be of little help.

No worries, here are few tips and online services that may still  help you uncover the identity of that unknown email sender.

#1. Find the sender’s location

Location of Email Sender

Open the header of the email message and look for lines that say “Received: from” followed by an IP address in square brackets. If there are multiple entries, use the IP address mentioned in the last entry.

Now paste the IP address in this trace route tool and you should get a fairly good idea about the location of the email sender.

#2. Reverse email search with Facebook

Facebook email search

Facebook has 450 million users worldwide and there’s a high probability that the sender may also have a profile on Facebook.

Unlike LinkedIn and most other social networks, Facebook lets you search users by email address so that should make your job simpler. Just paste the email address of the sender into the Facebook search box and you’ll immediately know if a matching profile exists in the network.

If you are able to locate that person on Facebook, download his profile picture and then upload it to Google Images (click the camera icon in the search box). This acts as a reverse image search engine so you can locate his other social profiles where he may have used the same picture.

#3. Check all the other Social Networks

You can use a service like Knowem to quickly determine if a profile with a particular username exists in any of the social networks.

If the email address of the send is something like green_peas@hotmail.com, there’s a probably that he or she may have created accounts of some other social network using the same alias “green_peas” – put that in knowem.com to confirm.

#4. People Search

Reverse Email Search

Finally, if nothing works, you should try a people search service like Pipl and Spokeo – both services let you perform reverse email lookups but Spokeo has a more comprehensive database than Pipl.

Other than regular web documents, Spoke also scans social networks and even the whois information of domain names to find any bit of information associated with an email address. However, some of the results returned by Spokeo are only available to subscribers.

Also see: Find Postal Addresses with Google Maps