Sendgrid - Unity Email using Web API

sgWeb

public void SendSendgridEmailWebAPI () {
  string url = "https://sendgrid.com/api/mail.send.json?";
  
  url += "to=" + toEmail;
  url += "&from=" + fromEmail;
  
  //you have to change every instance of space to %20 or you'll get a 400 error
  string subjectWithoutSpace = subject.Replace(" ", "%20");
  url += "&subject=" + subjectWithoutSpace;
  string bodyWithoutSpace = body.Replace(" ", "%20");
  
  url += "&text=" + bodyWithoutSpace;
  url += "&x-smtpapi=" + xsmtpapiJSON;
  url += "&api_user=" + api_user;
  url += "&api_key=" + api_key;
  
  WWW www = new WWW(url);
  StartCoroutine(WaitForRequest(www));
}

IEnumerator WaitForRequest(WWW www)
{
  yield return www;

  // check for errors
  if (www.error == null)
  {
      Debug.Log("WWW Ok! Email sent through Web API: " + www.text);
  } else {
      Debug.Log("WWW Error: "+ www.error);
  }    
}