如何使用PHP来混淆电子邮件地址,以免被垃圾邮件发送者收集？

    var email = "example" + "@" + "gmail" + "." + "com";
    document.write("<a href='mailto:" + email + "'>" + email + "</a>");
</script>

<?php
$email = "example@gmail.com";
$image = imagecreatetruecolor(strlen($email) * 10, 20);
$bgColor = imagecolorallocate($image, 255, 255, 255);
$textColor = imagecolorallocate($image, 0, 0, 0);
imagefill($image, 0, 0, $bgColor);
imagestring($image, 5, 0, 0, $email, $textColor);
header("Content-type: image/png");
imagepng($image);
imagedestroy($image);
?>

<?php
$email = "example@gmail.com";
$audio = "email.mp3";
$cmd = "echo \"$email\" | ffmpeg -i - -ar 44100 -ac 2 -ab 192k -f mp3 $audio";
exec($cmd);
header("Content-type: audio/mpeg");
readfile($audio);
unlink($audio);
?>

<?php
include "phpqrcode/qrlib.php";
$email = "example@gmail.com";
QRcode::png($email, "email.png");
header("Content-type: image/png");
readfile("email.png");
unlink("email.png");
?>

<?php
$email = "example@gmail.com";
$key = "mysecretkey";
$iv = "mysecretiv";
$encryptedEmail = openssl_encrypt($email, "AES-256-CBC", $key, 0, $iv);
// 将加密后的电子邮件地址存储在数据库中
// ...
// 从数据库中获取加密后的电子邮件地址
// ...
$decryptedEmail = openssl_decrypt($encryptedEmail, "AES-256-CBC", $key, 0, $iv);
echo $decryptedEmail;
?>