How to find who an email address is registered to

Have you ever received an e-mail and said to yourself, "Who is this from? I don't recognise that e-mail address!" Or maybe you've seen an e-mail address while cruising around online, and wondered, "Can I find out who the owner of that address is?"

The answer depends on two things. First, is it a free e-mail address from a service such as Hotmail, or an e-mail address associated with a purchased domain name? Second, does owner of the email address want his information to be private?

Look at the email address.There are two parts to it. The part that comes before the "@" symbol is the username. The part that comes after the "@" symbol is a domain name.

Go to the Whois database (see link in Resources below). This is a database of information concerning domain names. You can also use the Whois site if the domain name has a country code in it (such as "co.uk")

Let's say the email address is [email protected]. The part that you can investigate with the Whois database is the "xyz.com" part (the domain name).

Find the Whois search box and type in the domain name of the email address you want to investigate.

Do not type in the "http://" or the "www."

Click the "Search" button.

You are now looking at the Whois results displayed for the domain name you typed in.

Scroll down to the detailed information. It starts at the line that says "Registrant."

As long as there are no privacy options in force for this domain name, you are now looking at various facts about the domain name. These facts include personal information for the technical contact and the administrative contact, such as their name and e-mail address. Often, this gives you enough information to figure out who the owner of the "unknown" e-mail address is.

If your exact e-mail address isn't listed for one of the contacts, follow up by getting in touch with one of the listed contacts. Ask them who your mystery e-mail address belongs to.

If you don't see any personal data listed about the domain name contacts, it's likely that the owners purchased the domain via a "proxy" service in order to increase their privacy. In this situation, there's no personal information about the contacts listed--and its time to use other options for locating the owner of the email address.

Search for the email address at social networking sites that you think the owner of your mystery e-mail address may be a part of. Some examples are Facebook, MySpace, and LinkedIn and Google+. First create a profile with these sites, then do the search for your mystery e-mail address.

Sign up for an account with Yahoo!, Windows Live or Google+ and search for profiles that have your mystery e-mail address listed.