How to send multiple attachment in single mail in php

Following the reusability principles, you can use https://github.com/PHPMailer/PHPMailer

<?php
require 'PHPMailerAutoload.php';

$mail = new PHPMailer;

$mail->isSMTP();                                      // Set mailer to use SMTP
$mail->Host = 'smtp1.example.com;smtp2.example.com';  // Specify main and backup server
$mail->SMTPAuth = true;                               // Enable SMTP authentication
$mail->Username = 'jswan';                            // SMTP username
$mail->Password = 'secret';                           // SMTP password
$mail->SMTPSecure = 'tls';                            // Enable encryption, 'ssl' also accepted

$mail->From = '[email protected]';
$mail->FromName = 'Mailer';
$mail->addAddress('[email protected]', 'Josh Adams');  // Add a recipient
$mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
$mail->addAttachment('/tmp/image.jpg', 'new.jpg');    // Optional name                               

$mail->Subject = 'Here is the subject';
$mail->Body    = 'This is the HTML message body <b>in bold!</b>';
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

if(!$mail->send()) {
   echo 'Message could not be sent.';
   echo 'Mailer Error: ' . $mail->ErrorInfo;
   exit;
}

echo 'Message has been sent';

Source: How to attach two or multiple files and send mail in PHP

This is what I came up with for multiple files with form file name userfile:

for($ct=0;$ct<count($_FILES['userfile']['tmp_name']);$ct++)
{
    $uploadfile = tempnam(sys_get_temp_dir(), sha1($_FILES['userfile']['name'][$ct]));
    $filename =$_FILES['userfile']['name'][$ct];
    if (move_uploaded_file($_FILES['userfile']['tmp_name'][$ct], $uploadfile)) {
        $mail->addAttachment($uploadfile, $filename);
    }

}

if ($mail->send()) {
    echo "Sent";
} else {
    echo "Mailer Error: " . $mail->ErrorInfo;
}