Bulk Email Verifier - Clean up your large mailing lists before you use them. Clean list increases your reputation in MailChimp, AWeber, or Campayn.
Hunter - Find all the email addresses related to a domain
Email Verifier - Email verifier app lets you verify email.
MailDump Verifier - Powerful Emails Verifying Tool that helps verify email address or validate email addresses
Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI
Find Email Address - Highly Accurate Email Finder and Verifier