We moved to Drupal from another CMS about a year ago, and we still get 100s of "page not found" log entries each day for paths that were for our old site that don't exist on the new site. By checking IPs, I have concluded that most of these are from Google's indexer, but not all.
I add redirects when I can, but most of the links are to some meaningless tokenized path that our old CMS used. I feel like there is probably something I should be doing to flag bad paths for Google/SEO/whatever.
Is there a best practice for what to do with old broken links?