Elucify - A completely free software tool that uses crowdsourced data to find business email addresses
V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Lead Forensics - B2B website analytics and lead generation.
Adobe Audience Manager - Adobe Audience Manager is a data management platform that integrates online and offline data to deliver a unified view of all your audiences
FindThatLead Prospector - Feed your sales team with daily leads.
Clearbit - Clearbit provides Business Intelligence APIs