PHP system email sending function

/**
 * 功能：系统邮件发送函数
 * @param string $to    接收邮件者邮箱
 * @param string $name  接收邮件者名称
 * @param string $subject 邮件主题
 * @param string $body    邮件内容
 * @param string $attachment 附件列表
 * @return boolean
 */
function send_mail($to, $name, $subject = '', $body = '', $attachment = null, $config = '') {
    $config = is_array($config) ? $config : C('SYSTEM_EMAIL');
    import('PHPMailer.phpmailer', VENDOR_PATH);         //从PHPMailer目录导class.phpmailer.php类文件
    $mail = new PHPMailer();                           //PHPMailer对象
    $mail->CharSet = 'UTF-8';                         //设定邮件编码，默认ISO-8859-1，如果发中文此项必须设置，否则乱码
    $mail->IsSMTP();                                   // 设定使用SMTP服务
//    $mail->IsHTML(true);
    $mail->SMTPDebug = 0;                             // 关闭SMTP调试功能 1 = errors and messages2 = messages only
    $mail->SMTPAuth = true;                           // 启用 SMTP 验证功能
    if ($config['smtp_port'] == 465)
        $mail->SMTPSecure = 'ssl';                    // 使用安全协议
    $mail->Host = $config['smtp_host'];                // SMTP 服务器
    $mail->Port = $config['smtp_port'];                // SMTP服务器的端口号
    $mail->Username = $config['smtp_user'];           // SMTP服务器用户名
    $mail->Password = $config['smtp_pass'];           // SMTP服务器密码
    $mail->SetFrom($config['from_email'], $config['from_name']);
    $replyEmail = $config['reply_email'] ? $config['reply_email'] : $config['reply_email'];
    $replyName = $config['reply_name'] ? $config['reply_name'] : $config['reply_name'];
    $mail->AddReplyTo($replyEmail, $replyName);
    $mail->Subject = $subject;
    $mail->MsgHTML($body);
    $mail->AddAddress($to, $name);
    if (is_array($attachment)) { // 添加附件
        foreach ($attachment as $file) {
            if (is_array($file)) {
                is_file($file['path']) && $mail->AddAttachment($file['path'], $file['name']);
            } else {
                is_file($file) && $mail->AddAttachment($file);
            }
        }
    } else {
        is_file($attachment) && $mail->AddAttachment($attachment);
    }
    return $mail->Send() ? true : $mail->ErrorInfo;
}