It's actually pretty most of the time to discover who owns a specific email address, but the method depends on the type of email address in question. Here are the best ways to find out.
This seems like a pretty obvious solution, and sometimes, it is! People tend to post their email addresses on social media websites, and other sites they've signed up to. You can often find who owns an email address by searching for it in Google.
Domain email addresses
Domain names are another handy clue into who owns a particular email address. If the email you're looking for information about is something like "Frank @ frankswebsite.com" then you can navigate to frankswebsite.com to try to find some more information about who Frank is.
Send an email
The final option is a bit more creepy, depending on why you're after the information. You could email the person in question to ask who they are, although you're unlikely to receive a response unless it's a business address or they believe they know who you are already.