Hunter - Find all the email addresses related to a domain
lemlist - Send emails that get replies 💌
AnyMailFinder.com - Find anyone's email address
SalesProspect.io - Choose the top Salesforce LinkedIn integration: our Chrome Extension for Salesforce LinkedIn brings LinkedIn contacts into Salesforce.
EmailMatcher - Find anyone's email address in a matter of seconds, for free
Apollo.io - Apollo’s predictive prospecting, sales engagement, and actionable analytics help the teams to reach its full revenue potential.