title: "message": "Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authoriz LARAVEL
body: <p>i got this error when i try to test method in my controller </p>
  
  <pre><code> GuzzleHttp\Exception\ClientException: Client error: `POST https://api.mailgun.net/v3/sandbox22f99fb37d4a4953a7b8d84cf89d1147.mailgun.org/messages.mime` resulted in a `400 BAD REQUEST` response:
  {
    "message": "Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authoriz (truncated...)
  </code></pre>