I’ve been install Calyptix AccessEnforcer units recently in several SBS shops, both SBS 2003 and SBS 2008. The AE is a fully featured network security appliance, and comes in various models to fit different size organizations. What I like about Calyptix is its single price — no extra costs for end user licenses or to enable various features. It interfaces nicely with Active Directory for user level filtering and email quarantine. I plan to do more posts in the future on implementing SBS and Calyptix together.