All of our Shared Server packages come with SpamAssassin. You can enable SpamAssassin in your cPanel. If you don't see the option in your account, please Contact Support and ask them to change your cPanel skin to one that supports SpamAssassin.
SpamAssassin does a pretty good job at blocking spam, but we also offer a superior option called "Spamalizer" which uses advanced heuristics and community-based algorithms to identify and block spam. It runs automatically without you needing to configure or alter it. Spamalizer is available as an upgrade for any of our accounts. To order, please log in to your chi.midphase.com account or contact our Billing team.