Message could not be sent. Mailer Error: object(PHPMailer\PHPMailer\Exception)#2 (7) {
  ["message":protected]=>
  string(24) "Invalid address:  (to): "
  ["string":"Exception":private]=>
  string(0) ""
  ["code":protected]=>
  int(0)
  ["file":protected]=>
  string(45) "/var/www/register/PHPMailer/src/PHPMailer.php"
  ["line":protected]=>
  int(1079)
  ["trace":"Exception":private]=>
  array(2) {
    [0]=>
    array(5) {
      ["file"]=>
      string(45) "/var/www/register/PHPMailer/src/PHPMailer.php"
      ["line"]=>
      int(1001)
      ["function"]=>
      string(21) "addOrEnqueueAnAddress"
      ["class"]=>
      string(29) "PHPMailer\PHPMailer\PHPMailer"
      ["type"]=>
      string(2) "->"
    }
    [1]=>
    array(5) {
      ["file"]=>
      string(27) "/var/www/register/index.php"
      ["line"]=>
      int(28)
      ["function"]=>
      string(10) "addAddress"
      ["class"]=>
      string(29) "PHPMailer\PHPMailer\PHPMailer"
      ["type"]=>
      string(2) "->"
    }
  }
  ["previous":"Exception":private]=>
  NULL
}