smtpプロトコルphpでemail関数を送信(メール)

ネット上でemailを送る関数を探して、ほとんど探し当てていないで、メールを送る類があって、自分で1つのsmtpのを書いてみましたが、メールを送るのはまあまあですが、まだどのように添付ファイルを送るか分かりません.まず記録して、それから研究して、ゆっくり更新します.
163のsmtpをテストし、送信できます.
 
 

function sendEmail($host, $port=25, $check=0, $username='', $password='', $fromemail, $toemail, $fromName=''
	, $toName='', $subject='', $message='', $additional='', $charset='utf-8')
{
	$CRLF = "\r
";
	$fromName = trim($fromName) == '' ? $fromemail : $fromName;
	$toName = trim($toName) == '' ? $toemail : $toName;
	$send_from = "=?$charset?B?".base64_encode($fromName)."?= <$fromemail>";
	$send_to = "=?$charset?B?".base64_encode($toName)."?= <$toemail>";
	$send_subject = "=?$charset?B?".base64_encode(str_replace(array("\r","
"), array('',' '),$subject)).'?=';
	$send_message = chunk_split(base64_encode(str_replace("\r
.", " \r
..", str_replace("
", "\r
", 
		str_replace("\r", "
", str_replace("\r
", "
", str_replace("
\r", "\r", $message)))))));
	$additional = "To: {$send_to}{$CRLF}From: {$send_from}{$CRLF}MIME-Version: 1.0{$CRLF}Content-type: text/html; charset=$charset{$CRLF}{$additional}Content-Transfer-Encoding: base64{$CRLF}";
	$fp = fsockopen($host, $port, $errno, $errstr);
	if (!$fp)
	{
		return 'SCE'; //smtp connect error
	}
	if (strncmp(fgets($fp, 512), '220', 3) != 0)
	{
		return 'SCE'; //smtp connect error
	}
	fwrite($fp, "EHLO $fromName{$CRLF}");
	if ($check)
	{
		while ($rt=strtolower(fgets($fp, 512)))
		{
			if (strpos($rt, "-") !== 3 || empty($rt))
			{
				break;
			}
			elseif (strpos($rt, "2") !== 0)
			{
				return "AE";//auth error
			}
		}
		fwrite($fp, "AUTH LOGIN{$CRLF}");
		if (strncmp(fgets($fp, 512), '334', 3) != 0)
		{
			return "ALE";//auth login error
		}
		fwrite($fp, base64_encode($username).$CRLF);
		if (strncmp(fgets($fp,512), '334', 3) != 0)
		{
			return "ALUE";//auth login username error
		}
		fwrite($fp, base64_encode($password).$CRLF);
		if (strncmp(fgets($fp, 512), '235', 3) != 0)
		{
			return 'ALPE';//auth login password error
		}

	}
	$from = preg_replace("/.*\<(.+?)\>.*/", "\\1", $fromemail);
	fwrite($fp, "MAIL FROM: <$from>$CRLF");
	if (strncmp(fgets($fp, 512), '250', 3) != 0)
	{
		return 'EFE'; //email from error
	}
	fwrite($fp, "RCPT TO: <$toemail>$CRLF");
	if (strncmp(fgets($fp,512), '250', 3) != 0)
	{
		return 'ETE';//email toemail error
	}
	fwrite($fp, "DATA$CRLF");
	if (strncmp(fgets($fp, 512), '354', 3) != 0)
	{
		return 'EDE';//email data error
	}
	$msg  = "Date: ".Date("r").$CRLF;
	$msg .= "Subject: $send_subject".$CRLF;
	$msg .= $additional.$CRLF;
	$msg .= $send_message.$CRLF.".".$CRLF;
	fwrite($fp, $msg);
	$lastmessage = fgets($fp, 512);
	if (substr($lastmessage, 0, 3) != 250)
	{
		return 'ESE';//email send error
	}
	fwrite($fp, "QUIT\r
");
	fclose($fp);
	return 'OK';
}