通过PHP发送邮件

Question

我正在创建一个免费转发电子邮件地址系统，并在不久前问过这个问题。我想做的是将电子邮件转发给真实的电子邮件地址，同时保持标题不变。是否有任何理由说明以下代码无效：

#!/usr/bin/php -q
<?php
$fd = fopen("php://stdin", "r");
$email = "";
while (!feof($fd)) {
    $email .= fread($fd, 1024);
}
fclose($fd);

$lines = explode("\n", $email);

$to = "";
$from = "";
$subject = "";
$headers = "";
$message = "";
$splittingheaders = true;

$beforecheck = str_ireplace("to:", "", $to);
$checkdatabase = str_ireplace("@virtualparalegal.com", "", $beforecheck);

mysql_connect("localhost", "virtucb3_admin", "Instant11!") or
    die("Could not connect to the Database, the Database returned this error: " . mysql_error());
mysql_select_db("virtucb3_wordpress");

$result = mysql_query("SELECT user_nicename, user_email FROM wp_users WHERE `user_nicename` = $checkdatabase");

    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
    if ( $row["user_nicename"] == "$checkdatabase") {
        $to = ($row["user_email"]);
    }
    else {
        $to = "info@virtualparalegal.com";
    }
}

for ($i=0; $i<count($lines); $i++) {
    if ($splittingheaders) {
        $headers .= $lines[$i]."\n";

        if (preg_match("/^Subject: (.*)/", $lines[$i], $matches)) {
            $subject = $matches[1];
        }
        if (preg_match("/^From: (.*)/", $lines[$i], $matches)) {
            $from = $matches[1];
        }
    } else {
        $message .= $lines[$i]."\n";
    }

    if (trim($lines[$i])=="") {
        $splittingheaders = false;
    }
}


mail($to, $subject, $message, $headers);
?>

提前谢谢大家。