Hunter - Find all the email addresses related to a domain

ZabaSearch - Find people free with Zabasearch directory engine that includes free people search, reverse phone number lookup, address lookup, and more.

AnyMailFinder.com - Find anyone's email address

RealPeopleSearch - RealPeopleSearch is a web-based software that allows you to get the basic and public record of the concerned person within a few minutes by providing little information.

AeroLeads - AeroLeads is a lead generation software which finds prospects with email and phone number.

Numlooker - Numlooker is a web-based tool that is used to reverse the phone number that you have received.