add: kickbox

fix: free variant domain

fix: cors enabled

README.md

@@ -407,6 +407,7 @@ API | Description | Auth | HTTPS | CORS |
 | [apilayer mailboxlayer](https://mailboxlayer.com) | Email address validation | No | Yes | Unknown |
 | [Cloudmersive Validate](https://cloudmersive.com/validate-api) | Validate email addresses, phone numbers, VAT numbers and domain names | `apiKey` | Yes | Yes |
 | [EVA](https://eva.pingutil.com/) | Validate email addresses | No | Yes | Yes |
+| [Kickbox](https://open.kickbox.com/) | Email verification API | No | Yes | Yes |
 | [Lob.com](https://lob.com/) | US Address Verification | `apiKey` | Yes | Unknown |
 | [Postman Echo](https://www.postman-echo.com) | Test api server to receive and return value from HTTP method | No | Yes | Unknown |
 | [PurgoMalum](http://www.purgomalum.com) | Content validator against profanity & obscenity | No | No | Unknown |