Elucify - A completely free software tool that uses crowdsourced data to find business email addresses
Crunchbase - Crunchbase is a platform for discovering industry trends, investments, and news about companies around the world.
Lead Forensics - B2B website analytics and lead generation.
CB Insights - CB Insights is a company database for the venture capital and corporate development community.
FindThatLead Prospector - Feed your sales team with daily leads.
Tracxn - data on companies