Email Verification is the process of verifying an email address is valid and improving the odds that it belongs to a real person. The whole purpose of email verification is to ensure that a real person with a valid email address will receive and interact with the sent email.
ALL-IN-CRM has own build-in email verification system. This system can verify the email addresses before you send mail to customers. Our CRM will verify the email address in all ALL-IN-CRM Portal ( in Customer Profile, Compose, Campaigns newsletter and other )
You can use Third-party sites for an email verification but this is much more work and not free.