To add Guardian Mail
  1. In your Cisco Email Security Appliance, go to “Mail Policies” -> “HAT Overview”
  2. Click on the BLACKLIST or BLOCKED_LIST sender group (this depends on which version of the software you are running)
  3. Click Edit settings and under the DNS lists section, add <APIKEY>.combined.mail.abusix.zone. Replace <APIKEY> with “Your API key” from your account in app.abusix.com.