LinkAce has a nice feature called Link Checks. If you set up your cron correctly, LinkAce will regularily take a chunk of links from your collection and check if the links are still accessible.
With the help of the cron, LinkAce will perform the Link Check every hour. When started, LinkAce pulls 100 links from the database and then run the check on each link.
200within a timespan of 5 seconds, the link is considered fine.
302, the page was moved.
If LinkAce found at least one moved link or one broken link, it will send an email to the user containing details about the moved or broken links. The user can then react to this and check what happened to the link.
Moved or broken links are highlighted in the user interface.