Redirects to the Free API page

Fixes the issue #1307

README.md

@@ -137,7 +137,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Freelancer](https://developers.freelancer.com) | Hire freelancers to get work done | `OAuth` | Yes | Unknown |
 | [Gmail](https://developers.google.com/gmail/api/) | Flexible, RESTful access to the user's inbox | `OAuth` | Yes | Unknown |
 | [Google Analytics](https://developers.google.com/analytics/) | Collect, configure and analyze your data to reach the right audience | `OAuth` | Yes | Unknown |
-| [MailboxValidator](https://www.mailboxvalidator.com/api-single-validation) | Validate email address to improve deliverability | `apiKey` | Yes | Unknown |
+| [MailboxValidator](https://www.mailboxvalidator.com/api-email-free) | Validate email address to improve deliverability | `apiKey` | Yes | Unknown |
 | [mailgun](https://www.mailgun.com/) | Email Service | `apiKey` | Yes | Unknown |
 | [markerapi](http://www.markerapi.com/) | Trademark Search | No | No | Unknown |
 | [Trello](https://developers.trello.com/) | Boards, lists and cards to help you organize and prioritize your projects | `OAuth` | Yes | Unknown |