Firstly we would recommend that you do not have any email account set up as a "Catch-all" email address. This is only possible on our older Linux and Windows hosting packages, and on our VPS plans. We don't support the use of catch-all email addresses in our new cp.blacknight.com shared hosting plans for anti-spam and server-performance reasons.
If your email is hosted on our Shared Hosting system you should enable the SpamExperts content filtering system to protect your email accounts - note that this could already be enabled; see https://help.blacknight.com/entries/30010951-Spam-Filtering-On-Shared-Hosting-Packages-SpamExperts.
Lastly we offer a premium anti-spam service with both black and whitelist support; ask our sales team for more information.