How to Avoid losing traffice to non-existing pages on your site
If you happened to delete a page from your site, change a page URL, or if a different site has been hosted under your domain before, you might be getting a lot of hits to non-existing pages on your site. They usually come from obsolete search engine records, not updated bookmarks, links from other sites, or simply mistyped URLs.
Instead of losing that traffic you may have it directed to some page from your site, e.g to your Home page. From Manage Pages option in Control Panel find the page to which the traffic should be redirected and set it as your custom not found page. All hits to non-existing pages on your site will now be redirected to your custom not found page.