Performing the Threat Response action requires the following:
Your Trustifi plan must be integrated with your Exchange server. To perform this integration, navigate to “Inbound Management” > “Plan Settings” and scroll down to “Exchange integration”The mailbox(es) must be connected to Office365.The mailbox(es) must be “protected” by Trustifi. You can view the protection status of each mailbox in the “Mailbox Management” page (“Protected”/”Exposed”).