phpmailer ---> Could not instantiate mail function

[amils21]

me de el error: Could not instantiate mail function

Código PHP:

  <?php
require 'mails/class.phpmailer.php';
require 'mails/class.smtp.php';



$mail = new PHPMailer();
                $mail->Host = "localhost";
                $mail->From = "[email protected]";
                $mail->FromName = "amilkar contreras casttro";
                $mail->Subject = "Subject del correo";
                $mail->AddAddress("[email protected]","Amilkar");
                
                $body  = "Hola <strong>amigo</strong><br>";
                $body .= "probando <i>PHPMailer<i>.<br><br>";
                $body .= "<font color='red'>Saludos</font>";
                $mail->Body = $body;
                $mail->AltBody = "Hola amigo\nprobando PHPMailer\n\nSaludos";
                $mail->AddAttachment("images/foto.jpg", "foto.jpg");
                $mail->AddAttachment("files/demo.zip", "demo.zip");
                $mail->Send();
                if(!$mail->Send()) {//finalmente enviamos el email
                        ?>
                        <script>
                        alert("no se envio en correo: por <?php echo $mail->ErrorInfo; ?>");
                        </script>
                            <?php
                       //si no se envía correctamente se muestra el error que ocurrió
                    } else {
                       ?>
                        <script>
                            alert("Su contraseña fue enviadfa a su correo");
                        </script>
                
                          <?php
                       echo '<meta http-equiv="Refresh" content="2;url=olvido_contrasena.php"> ';
                       }
?>