When you register for an account, Clearout sends you an email with a link in it, so you can activate your account. You just have to click on that link, and you're all set to start verifying your list.
Check all folders/tabs (Spam, Promotional, deleted) to locate the email. If you can't locate the email, then it's possible that you misspelled your email address on the registration screen. Please try re-registering, and if your email was misspelled, you will be allowed to register under the correct email address.
Sometimes, your spam filters might be rejecting our emails. It's important that you are able to receive emails from us, so you can access the files you validate. If you think you are not receiving our emails because of your spam filters, please contact us at email@example.com and we will be happy to assist you in solving this issue.