The engine can send Notifications to you whenever someone posts a comment on one of your entries and whenever one of your entries receives a Trackback, Pingback or a referral from another site. You can enable any of these notification types using the checkboxes in this section of the configuration page. For the engine to be able to reach you, you also need to provide a valid SMTP server address in the SMTP Server Address field. The value may be a DNS name or a numeric IP address.