向从mysqli数据库检索到的多个收件人发送一封电子邮件

我正在尝试创建一个php页面，一旦数据库中的某个项目更新，它就会向链接到该项目的任何用户发送电子邮件。我的代码检索电子邮件地址，并将它们放在数组中。问题是电子邮件没有发送，我哪里出了问题？

<?php
require_once 'config/init.php';
$id = $_GET['id'];
$mysqli_conn = new mysqli($db['hostname'],$db['username'],$db['password'], $db['database']);
        if ($mysqli_conn -> connect_errno) {//check the connection
            print "Failed to connect to MySQL: (" . $mysqli_conn -> connect_errno . ") " . $mysqli_conn -> connect_error;
        }
$result = $mysqli_conn->query("SELECT * From Logins")
$headers.= "'r'n";
$headers.= "Content-type: text/html'r'n";
$to = '';
$headers.="Bcc: ";
while ($row = $result->fetch_array()) {
    $headers.=$row['Email'].", ";
    //$to.=$row['Email'].", ";
}
$subject = "Subject";
$headers.="'r'n";
$mailbody = "Body of email";
$mailResult = @mail($to, $subject, $mailbody, $headers);

print $to;
print $subject;
print $mailbody;
print $headers;

?>