Hi :-)

in config local add

// anti-flood_time : number of seconds between 2 comments : 0 to disable
$conf['anti-flood_time'] = 60;

// qualified spam comments are not registered (false will register them
// but they will require admin validation)
$conf['comment_spam_reject'] = true;

// maximum number of links in a comment before it is qualified spam
$conf['comment_spam_max_links'] = 3;

and update