The AntiSpam module is available as part of the Client Security Business, Endpoint Protection Business and Managed Endpoint Security solutions.
If you check the option Use spam filter, client email traffic will be checked for possible spam mails. You can configure a warning message that will be added to the subject line when an email is identified as spam or falls under suspicion of being spam.
If the Microsoft Outlook plugin has been enabled, incoming spam mails will be moved to the AntiSpam folder. For other e-mail clients, spam mails can be automatically moved to a dedicated spam folder by defining a filter rule that matches the spam warning in the subject. To configure AntiSpam settings when using Microsoft Exchange, see Exchange settings > AntiSpam.