<?php
  $sFROM   = $sCC     = $sTO  =   $sBCC   = "example@email.com";
  $sSUB    = "Email with attachment";         // Subject

// use the MD5 algorithm to generate a unique random hash
$random_hash = md5(date('r', time()));
$headers = "From: $sFROM\r\nReply-To: $sTO";
$headers .= "\r\nContent-Type: multipart/mixed; boundary=\"PHP-mixed-".$random_hash."\"";
$attachFile = "C:\mail\test.xls";

$attachment = chunk_split(base64_encode(file_get_contents($attachFile)));

//define the body of the message.
ob_start(); //Turn on output buffering
?>
--PHP-mixed-<?php echo $random_hash; ?>
Content-Type: multipart/alternative; boundary="PHP-alt-<?php echo $random_hash; ?>"

--PHP-alt-<?php echo $random_hash; ?>
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

<h2>Hello World!</h2>
<p>Testing message here ...</p>

--PHP-alt-<?php echo $random_hash; ?>--

--PHP-mixed-$random_hash
Content-Type: application/vnd.ms-excel; name=".basename($attachFile)
Content-Transfer-Encoding: base64
Content-Disposition: attachment

<?php echo $attachment; ?>
--PHP-mixed-<?php echo $random_hash"; ?>--

<?php    

//copy current buffer contents into $message variable and delete current output buffer
$message = ob_get_clean();
//send the email
$mail_sent = mail( $sTO, $sSUB, $message, $headers );
//if the message is sent successfully print "Mail sent". Otherwise print "Mail failed"
echo $mail_sent ? "Mail sent\r\n" : "Mail failed\r\n";

?>