public function check_mime_detection()
    {
        $errors = array();
        $files  = array(
            'program/resources/tinymce/video.png' => 'image/png',
            'program/resources/blank.tiff'        => 'image/tiff',
            'program/resources/blocked.gif'       => 'image/gif',
        );

        foreach ($files as $path => $expected) {
            $mimetype = rcube_mime::file_content_type(INSTALL_PATH . $path, basename($path));
            if ($mimetype != $expected) {
                $errors[] = array($path, $mimetype, $expected);
            }
        }

        return $errors;
    }