想要使用php变量同时向两个用户发送php mail（）

Question

我试图使用php从我已转换为变量的用户输入信息中同时向两个不同的用户发送电子邮件。

<?php
$shipperemail = mysqli_real_escape_string($con, $_REQUEST['shipperemail']);
$receiveremail = mysqli_real_escape_string($con, $_REQUEST['receiveremail']);
$receiveremail = mysqli_real_escape_string($con, $_REQUEST['receiveremail']);
$email_from = "valueHandlers@me.com";
    $email_to = ".$shipperemail.";
    $email_to = ".$receiveremail.";
    $email_subject = "Tracking Code"; 
    $email_message .= "Tracking Code: ".$consignmentno."\n";
    $email_message .= "Sender Name: ".$shippername."\n";
    $email_message .= "Receiver Name: ".$receivername."\n";
    $email_message .= "Expected date of delevery: ".$shipmentexpected."\n";
    $email_message .= "Comments: ".$comments."\n";
    $email_message .= "for more update, folow the link Http://valuehandlers.com/track";

// create email headers
$headers = 'From: '.$email_from."\r\n".
'Reply-To: '.$email_from."\r\n" .
'X-Mailer: PHP/' . phpversion();
@mail($email_to, $email_subject, $email_message, $headers); 
?>

但是没有变量将邮件传递给变量电子邮件