TrueMail.io - TrueMail.io is an email checker service.
NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.
TheChecker.co - Accurate email verification at low prices.
ZeroBounce - Removes invalid emails from your list to prevent email bounces from ruining your deliverability.
Verimail - Clean up email-address lists of any size or use our powerful API for real-time verification.
Kickbox - Verify your email address lists with our drag and drop interface, or integrate into your app with our API. Prevent fake and bot account sign-ups by confirming your users are real humans with a real email address.