如何为PHP邮件处理脚本添加特定域名/后缀拦截功能？

你之前的代码失效原因 #

• 无效代码1：误用了未定义的$post变量（正确应为$_POST）；直接抛出异常却未做捕获处理，会导致页面崩溃；且即便抛出异常，后续邮件发送代码仍可能执行，等于没起到拦截作用。
• 无效代码2：在普通PHP脚本中使用private修饰方法是语法错误（这是类专属语法）；仅定义方法却从未调用，完全无法生效。

修改后的完整可用脚本 #

把拦截逻辑放在脚本最开头，验证不通过直接终止，不执行后续邮件发送：

<?php
// 自定义拦截的域名/后缀黑名单，可按需添加
$blacklist = [
    '@mail.ru',
    '@example.org',
    '@example.net'
];

// 获取提交的邮箱，为空则直接标记为拦截
$user_email = $_POST['email_quote'] ?? '';

$is_blocked = false;
// 先验证邮箱格式是否合法
if (!filter_var($user_email, FILTER_VALIDATE_EMAIL)) {
    $is_blocked = true;
} else {
    // 检查是否命中黑名单
    foreach ($blacklist as $blocked_suffix) {
        if (stripos($user_email, $blocked_suffix) !== false) {
            $is_blocked = true;
            break;
        }
    }
}

// 拦截处理：输出提示并终止脚本
if ($is_blocked) {
    echo "抱歉，该邮箱地址无法提交请求，请更换其他邮箱。";
    exit;
}

// 以下是原脚本的核心逻辑，仅在验证通过后执行
$mail = $user_email;

$to = "contact@editedemail.com";
$subject = "Online Website Quote Request";
$headers = "From: Website <no-reply@editedemail.com>";

$message = "
PERSONAL INFO";
$message .= "
First Name: " . $_POST['firstname_quote'];
$message .= "
Last Name: " . $_POST['lastname_quote'];
$message .= "
Email: " . $user_email;
$message .= "
Phone number: " . $_POST['phone_quote'];

$message .= "

Vehicle Details";
$message .= "
Year: " . $_POST['vehicle_year_quote'];
$message .= "
Make: " . $_POST['vehicle_make_quote'];
$message .= "
Model: " . $_POST['vehicle_model_quote'];

$message .= "

ADDTIONAL INFO";
$message .= "
Locked out of your vehicle? " . $_POST['option_1'];
$message .= "
Lost All Your Vehicle Keys? " . $_POST['option_2'];
$message .= "
Push to start ignition? " . $_POST['option_3'];
$message .= "
Require new key(s) made? " . $_POST['option_4'];
$message .= "
Require new remote(s) made? " . $_POST['option_5'];
$message .= "
Vehicle has keyless entry? " . $_POST['option_6'];

$message  .= "

ADDITIONAL NOTES";
$message .= "
Message: " . $_POST['message_quote'];

// 发送管理员通知邮件
$sentOk = mail($to,$subject,$message,$headers);

// 发送用户确认邮件（补全你之前截断的内容）
$usersubject = "Thank You";
$userheaders = "From: no-reply@editedemail.com";
$usermessage = "Your request has been successfully submitted. One of our staff will contact you shortly. If you require immediate assistance with your vehicle, please call our support line.";
mail($mail,$usersubject,$usermessage,$userheaders);

// 提交成功提示
echo "请求提交成功，我们会尽快联系您。";
?>

关键说明 #

1. 黑名单自定义：在$blacklist数组中添加需要拦截的域名后缀，比如@spam.com、@fake.org等。
2. 双重验证：先验证邮箱格式合法性，再检查是否命中黑名单，避免无效请求。
3. 彻底拦截：一旦检测到黑名单邮箱，用exit直接终止脚本，后续邮件发送逻辑完全不执行。
4. 用户反馈：给拦截请求明确的提示，避免用户困惑。

内容的提问来源于stack exchange，提问作者ManWithAPlan