求助：为PHP邮件伪造脚本添加Reply-To地址功能

要实现收件人回复邮件时发送到指定自定义邮箱的功能，需从前端表单添加输入项和后端邮件头处理两部分修改：

1. 前端表单添加Reply-To输入框 #

在现有表单的「From Email」字段后，新增用于输入回复目标邮箱的字段：

<br><b>Reply-To Email:</b><br>
<input type="text" name="replytoemail" size="50"><br>

2. 后端PHP添加Reply-To邮件头 #

在PHP处理逻辑中，获取Reply-To邮箱参数并追加到邮件头，注意邮件头之间必须用\r\n分隔：

// 获取Reply-To邮箱
$replytoemail = $_POST['replytoemail'];
// 追加Reply-To头到现有邮件头
if (!empty($replytoemail)) {
    $headers .= "\r\nReply-To: " . $replytoemail;
}

修改后的完整代码 #

<?php
if (isset( $_POST['submit'])) {
    $to = $_POST['toemail'];
    $subject = $_POST['subject'];
    $message = $_POST['message'];
    $fromemail = $_POST['fromemail'];
    $fromname = $_POST['fromname'];
    $replytoemail = $_POST['replytoemail']; // 新增：获取回复邮箱
    $lt = '<';
    $gt = '>';
    $sp = ' ';
    $from = 'From:';
    $headers = $from . $fromname . $sp . $lt . $fromemail . $gt;
    
    // 新增：添加Reply-To邮件头
    if (!empty($replytoemail)) {
        $headers .= "\r\nReply-To: " . $replytoemail;
    }
    
    mail($to, $subject, $message, $headers);
    header("Location: index.php?msg= Mail Sent!");
    exit();
}
?>
<html>

<head>
    <title>Spoof E-Mail using PHP</title>
</head>

<body bgcolor="#ffffcc" style="margin: 0 10%">
    <h2 align="center">
        Spoof E-Mail using PHP( Script By Arpit )
    </h2>
    <p style="margin-left:15px">
        <form action="index.php" method="POST">
            <b>From Name:</b><br>
            <input type="text" name="fromname" size="50"><br>
            <br><b>From Email:</b><br>
            <input type="text" name="fromemail" size="50"><br>
            <!-- 新增：Reply-To输入框 -->
            <br><b>Reply-To Email:</b><br>
            <input type="text" name="replytoemail" size="50"><br>
            <br><b>To Email:</b><br>
            <input type="text" name="toemail" size="50"><br>
            <br><b>Subject:</b><br>
            <input type="text" name="subject" size="50"><br>
            <br><b>Your Message:</b><br>
            <textarea name="message" rows="5" cols="46"></textarea><br><br>
            <input type="submit" name="submit" value="Send">
            <input type="reset" value="Reset">
        </form>
    </p>
    <?php if (isset($_GET['msg'])) {
        ?>
        <script>
            alert("Mail Sent!!");
        </script>
        <?php
    } ?>
    <h3 align="center" style="color: red;">
        Legal disclaimer:<br>Usage of use of this script for attacking targets without prior mutual consent is illegal. It's the end user's responsibility to obey all applicable local, state and federal laws. Developers assume no liability and are not responsible for any misuse or damage caused by this program
    </h3>
</body>
</html>

功能说明 #

新增的Reply-To邮件头会告知邮件客户端：当收件人点击回复时，默认将邮件发送到指定的自定义邮箱，而非伪造的发件人邮箱。代码中增加了非空判断，避免空值导致邮件头异常。

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