PHP function to send e-mail with attachments

mail_with_attachments.php

<?php
/*
Copyright (c) 2012, Manu Manjunath
All rights reserved.
 
Redistribution and use of this program in source/binary forms, with or without modification are permitted.
Link to this gist is preferred, but not a condition for redistribution/use.
*/

function mail_with_attachments($to, $subject, $message, Array $filepaths, $from = null, $replyto = null) {
	$uid = md5(uniqid(time()));
	$from = str_replace(array("\r", "\n"), '', $from);
	$headers = (empty($from) ? "" : "From: $from\r\n")
		. (empty($replyto) ? "" : "Reply-To: $replyto\r\n")
		. "MIME-Version: 1.0\r\n"
		. "Content-Type: multipart/mixed; boundary=\"$uid\"\r\n\r\n"
		. "This is a multi-part message in MIME format.\r\n"
		. "--$uid\r\n"
		. "Content-type: text/plain; charset=iso-8859-1\r\n"
		. "Content-Transfer-Encoding: 7bit\r\n\r\n"
		. "$message\r\n\r\n";
	foreach ($filepaths as $filepath) {
		if(!file_exists($filepath))
			continue;		
		$filename = basename($filepath);
		$file_contents = file_get_contents($filepath);
		$file_contents_base64 = base64_encode($file_contents);
		$content = chunk_split($file_contents_base64);
		$headers .= "--$uid\r\n"
			. "Content-Type: application/octet-stream; name=\"$filename\"\r\n"
			. "Content-Transfer-Encoding: base64\r\n"
			. "Content-Disposition: attachment; filename=\"$filename\"\r\n\r\n"
			. "$content\r\n\r\n";
	}
	$headers .= "--$uid--";
	return mail($to, $subject, "", $headers);
}