Using Link Validation, you can activate a scheduled job which will go through and check all the links on your website to look for broken links. EPiServer CMS will try to contact the target for the link to verify that it is responding.
Only links that are unchecked or have been checked earlier than the time when the job started will be returned. The job will continue until no more unchecked links are received from the database. If a large number of consecutive errors are found for external links, in case of a general network problem with the server running the site, the job will stop.
The result of the link validation job is made available as a report called Link Status, in the EPiServer CMS Report Center.