What happens if you do not set up redirect script after migrating from a different software? Do you get penalized from google? How long before google naturally finds the new links and drops the old ones? Is there a penalty? In my case, I have moved from ipb couple of days ago. Also, made some changes to forum structure since (deleted some forums, moved some posts around, renamed certain forums). Will the script work in this case or should I just let it be?