Cisco Cisco Email Security Appliance C160 Mode D'Emploi

Check the “Connecting host reverse DNS lookup (PTR) does not match the forward DNS lookup (A)” 
checkbox under Connecting Host DNS Verification.

Submit and commit your changes.

Now, senders for which reverse DNS lookups fail will match the SUSPECTLIST sender group and will 
receive the default action from the THROTTLED mail flow policy.

You can also configure host DNS verification via the CLI. See 

 for more information.

Create a new mail flow policy (for this example, it is named THROTTLEMORE) and configure it with 
more stringent throttling settings.

On the Mail Flow Policies page, click Add Policy

Enter a name for the mail flow policy, and select Accept as the Connection Behavior.

Configure the policy to throttle mail.

Submit and commit your changes.

Create a new sender group (for this example, it is named UNVERIFIED) and configure it to use the 
THROTTLEMORE policy:

On the HAT Overview page, click Add Sender Group

Select the THROTTLEMORE policy from the list.

Check the “Connecting host PTR record does not exist in DNS” checkbox under Connecting Host 
DNS Verification.