This email verification tool actually connects to the mail server and checks whether the mailbox exists or not, wipeout disposable email addresses from your email list.
ZeroBounce - Removes invalid emails from your list to prevent email bounces from ruining your deliverability.
Bulk Email Checker - Bulk Email Checker is an online service used to Verify and Clean Email Addresses. Its Easy to Use, Reliable and used by 1000's of Businesses.
Email Checker - Email Checker offers a real-time API and bulk validation for list cleaning.
Email Hippo - Email Hippo provides online email validation service for professional marketers and their clients.
verify-email.org - Improve Email Deliverability with Email Validation
NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.