May need to speak with the plugin author, but i would assume its using a custom post type, so you could filter the search results for only posts and pages with this PHP snippet:
add_action('pre_get_posts','search_filter');
function search_filter( $query ) {
if ( ! is_admin() && $query->is_main_query() ) {
if ( $query->is_search) {
$query->set('post_type', array('post', 'page') );
}
}
}
Would you be able to ask the Redirect plugin author?
If they can’t help hiding it from the search results, they should be able to tell us what the name of the post template is.