从.php重定向到index.html不起作用

Question

我有我的php文件，一旦他们收到确认他们发送的电子邮件后用户点击确定按钮，我就无法进入index.html。

<?php
$name = $_REQUEST['Name'];
$email = $_REQUEST['Email'];
$message = $_REQUEST['Message'];

$email_message = "
Name: ".$name."
Email: ".$email."
Message: ".$message."
";

mail ("info@email.com", "New inquiry", $email_message);

print '<script type="text/javascript">';
print 'alert("Your email has been sent! Someone will get in touch with you shortly. Thank You.")'; 
print '</script>'; 

header('Location: index.html'); 

?>