The email scan will notify you if your website or servers are sending spam, or are referenced in spam emails.
If this is the case, many email programs will ignore or classify emails from your site as spam. This means your customers and users may not receive the emails you send. To re-open communication with your customers, you must remove your site from these email blacklists.
For more information about the results of your SiteLock scan, please read: How do I see details on the issues SiteLock reports about my site?