MailDump Verifier - Powerful Emails Verifying Tool that helps verify email address or validate email addresses
BuiltWith - Find out the technology behind websites
Hunter - Find all the email addresses related to a domain
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Mail Dump - Powerful Extensions for email addresses extracting, verifying and finding
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.