code: protected function email($toAddr, $subject, $body)
      {
          $addHeadersStr = '';
          $fromAddr = $this->cfg['emailFrom'];
          if ($fromAddr) {
              $addHeadersStr .= 'From: '.$fromAddr;
          }
          \call_user_func($this->cfg['emailFunc'], $toAddr, $subject, $body, $addHeadersStr);
      }
docs: Send an email
  
  @param string $toAddr  To
  @param string $subject Subject
  @param string $body    Body
  
  @return void