Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI
BizProspex - BizProspex offers CRM data cleaning solutions.
NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.
RingLead - RingLead offers a complete end-to-end suite of products to clean, protect, and enhance company and contact information.
Email Verifier - Email verifier app lets you verify email.
TowerData - demographic data on email addresses