php str_replace用于带有邮件功能的循环中

Question

I have an html email message assigned to a variable before it is used in a loop, then in the loop I try to use str_replace to insert custom values into hooks. So in the below example I have an {email} hook which I'm trying to replace with the recipient's email address. My problem is that when I output $message_final to the browser the str_replace function seems to have done the job. But when I send the email out, all the emails are still left with the {email} hook, and it appears that str_replace hasn't worked. Any ideas what i'm missing here? Thanks.

$message = "HTML email message here";

while ($r = mysql_fetch_array($emails_list)) {
    $email =  $r["email"];
    $message_final = "";

    if(!empty($email)) {
        //Replace hook with something new like an email address
        $message_final = str_replace('{email}', $email, $message);
        mail($email, $subject, $message_final, $headers); 
    }
}

Answer 1

Ahhhhh! Palm to face!! It was something completely different causing the issue. In my mail header I had the message attached there, and I was calling str_replace in the wrong bit of the code. Thanks for all your replies guys :)