...We perform checks on both local username and domain name parts of the Email address syntax. Our system evaluate a score based on the username syntax risk, as well as some deep server verifications, such as: MX records existence, SMTP host, open ports, and the answers after a socket conversation between our server and the SMTP host. Our API will answer to your requests using the output format of your choice, with the results of several verifications, available to you from the different fields as described in our documentation. ...