PHP Mailer Class

<?php

class Mailer {
    protected $charset = 'UTF-8',
              $to,
              $from,
              $subject = '',
              $headers = array(),
              $attachments = array();

    public function setCharset($value) {
        $this->charset = $value;
    }

    public function encode($value) {
        return '=?' . $this->charset . '?B?' . base64_encode($value) . '?=';
    }

    public function setFrom($email, $name = null) {
        $this->from = $name ? $this->encode($name) . " <$email>" : $email;
    }

    public function setSubject($value) {
        $this->subject = $this->encode($value);
    }

    public function addHeader($header) {
        $this->headers[] = $header;
    }

    public function addAttachment($name, $data, $type =
            'application/octet-stream') {
        $name = $this->encode($name);
        $data = chunk_split(base64_encode($data));
        $this->attachments[] = compact('name', 'data', 'type');
    }

    public function send($to, $body, $is_html = 0) {
        if ($this->from) {
            $this->headers[] = 'From: ' . $this->from;
        }
        $content_type = 'Content-Type: text/' . ($is_html ? 'html' : 'plain') .
                '; charset=' . $this->charset;
        $content_transfer_encoding = 'Content-Transfer-Encoding: 8 bit';
        if ($count = count($this->attachments)) {
            $boundary = uniqid();
            $this->headers[] = 'Content-Type: multipart/mixed; boundary="' .
                    $boundary . '"';
            $body  = array("--$boundary", $content_type,
                "$content_transfer_encoding\r\n", $body);
            for ($i = 0; $i < $count; ++$i) {
                $body[] = "--$boundary";
                $body[] = "Content-Type: " . $this->attachments[$i]['type'] .
                        "; name=\"" . $this->attachments[$i]['name'] . "\"";
                $body[] = 'Content-Disposition: attachment';
                $body[] = "Content-Transfer-Encoding: base64\r\n";
                $body[] =  $this->attachments[$i]['data'];
            }
            $body = implode("\r\n", $body) . "--$boundary--";
        }
        else {
            $this->headers[] = $content_type;
            $this->headers[] = $content_transfer_encoding;
        }
        return @mail($to, $this->subject, $body, implode("\r\n",
                $this->headers));
    }

    public function html($to, $body) {
        return $this->send($to, $body, 1);
    }
}

?>