If you only use Scan feature without using the optional Mail Inbox Checker feature then this issue may appear from a specific mail server domain. The main reason behind this is that the email server where it connecting to verify that the email name address is a public email address server which returns bad response data to our built SMTP scanner system within the script or that destination mail server is protected over the firewall and can only be valid for MX destinations. Email Verifier Pro handles data only that it can get from external mail servers, it does not build up its own unknown data for you. But you can report any wrong results on our feedback page so we can try to look into it and resolve it if there’s a possibility. You can assign an incorrect response mail server to an unsupported domain list within the domain filter to skip those specific domain scans only if you do not plan to use the Inbox Checker feature OR alternatively, you can use second-level validation Mail Inbox Checker on top of the default scan and you will get 100% accurate response data.
Mail Inbox Checker feature is an optional feature that sends direct emails using dummy stored templates to validate the list. It requires external SMTP & IMAP mailbox connections to do this work which allows bulk email sending with no limits.
