Cold Email Hacks - Proven cold email templates and tactics for B2B startups
Hunter - Find all the email addresses related to a domain
Cold Email Analyzer by Mailshake - Real-time analysis of email subject lines and copy
AnyMailFinder.com - Find anyone's email address
Cold Email Generator - Quickly create a 5-touchpoint email campaign
RocketReach - RocketReach allows you to lookup email and phone for 250+ million professionals.