Cisco Cisco Email Security Appliance C160 Mode D'Emploi

A “listener” manages inbound email processing services that will be configured on a particular IP 
interface. Listeners only apply to email entering the Email Security appliance — either from your 
internal systems or from the Internet. Cisco AsyncOS uses listeners to specify criteria that messages 
must meet in order to be accepted and relayed to recipient hosts. You can think of a listener as an email 
listener (or even a “SMTP daemon”) running for IP addresses you specified above. 

For C370, C670, X1070, C380, C680 appliances: By default, the 

systemsetup

 command configures 

two listeners — one public and one private. (For more information on the types of listeners available, 
see 

.) 

For C170 appliances: By default, the 

systemsetup

 command configures one public listener for both 

receiving mail from the Internet and for relaying email from your internal network. See 

. 

When you define a listener, you specify the following attributes: 

A name (nickname) created by you to refer to the listener later. For example, the listener that accepts 
email from your internal systems to be delivered to the Internet may be called OutboundMail.

One of the IP interfaces (that you created earlier in the 

systemsetup

 command) on which to receive 

email.

The name of the machine(s) to which you want to route email (public listeners only). (This is the 
first 

smtproutes

 entry. See 

Whether or not to enable filtering based on SenderBase Reputation Scores (SBRS) for public 
listeners. If enabled, you are also prompted to select between Conservative, Moderate, or Aggressive 
settings.

Rate-limiting per host: the maximum number of recipients per hour you are willing to receive from 
a remote host (public listeners only).

The recipient domains or specific addresses you want to accept email for (public listeners) or the 
systems allowed to relay email through the appliance (private listeners). (These are the first 
Recipient Access Table and Host Access Table entries for a listener. See 

 and 

 for more 

information.)

The following examples of creating a public and private listener apply to C370, C670, X1070, C380, 
C680 appliances only. For C170 appliances, skip to the next section,