Perform the following steps in the Management Console tree:
If you want to enable or disable attachment and content filtering on an unassigned Security Server, select the node of this Security Server.
If you want to enable or disable attachment and content filtering on Security Servers included in a profile, expand the Profiles node and select the node of the profile for which you need to enable or disable attachment and content filtering on Security Servers.
Select the Server protection node.
Select the Protection for the Transport Hub role tab.
In the Attachment and content filtering dropdown section, select the Enable attachment and content filtering check box.
Click the Save button.
Attachment and content filtering is now enabled. The filtering rules will be available for configuration. If no rule is configured, attachment and content filtering is inactive.