code: function PostmarkErrorStatus(response) {
    MessagingServiceStatus.call(this, 'postmark');
  
    // There was an error when attempting to send message
    this.state.message = response.code + ': ' + response.message;
  
    // Catch internal server error
    if (response.status == 500) {
      this.state.code = this.StatusCodes.SERVICE_DOWN;
      return
    }
  
    // See http://developer.postmarkapp.com/developer-api-overview.html for status error codes
    if (response.code == 400) this.state.code = this.StatusCodes.DATA_REJECTED;
    else if (response.code == 401) this.state.code = this.StatusCodes.DATA_REJECTED;
    else if (response.code == 405) this.state.code = this.StatusCodes.LIMIT_EXCEEDED;
    else if (response.code == 406) this.state.code = this.StatusCodes.DATA_REJECTED;
    else if (response.code == 507) this.state.code = this.StatusCodes.DATA_REJECTED;
    else if (response.code == 522) this.state.code = this.StatusCodes.DATA_REJECTED;
    else this.state.code = this.StatusCodes.DEFAULT;
  }
docs: /*
  Error Status
  
  @param response     JSON response object from Postmark service