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