Our shared hosting server comes with SpamAssassin, the most trusted spam killer software. SpamAssassin is not enabled by default, you have to login to cPanel and enable it. Depending on your configuration, spam emails will be filter by their scores and marked with ** SPAM ** in the subject field. If SpamBox (another component comes with SpamAssassin) is enabled, spam emails will be delivered to a separate inbox, not main inbox. You still can check that special inbox later to find those fail-positive emails.