Cisco Cisco Email Security Appliance C190 Guida Utente

Figure 3-4 further illustrates the differences between the default settings of public 
and private listeners. A public listener is intended to receive email from the 
internet. The public listener receives connections from many hosts and directs 
messages to a limited number of recipients. Conversely, a private listener is 
intended to receive email from your internal network. The private listener receives 
connections from a limited (known) number of hosts and directs messages to 
many recipients.

C10/100 customers: By default, the System Setup Wizard walks you through 
configuring one public listener for both receiving mail from the Internet and for 
relaying email from your internal network. That is, one listener can perform both 
functions. 

Later in the chapter, these differences will be demonstrated in the Host Access 
Table and Recipient Access Table for each type of listener. 

 illustrates a typical Email Gateway configuration created by the 

System Setup Wizard Setup Wizard (or CLI 

systemsetup

 command) on IronPort 

X1000/1050/1060, C60/600/650/660, and C30/300/350/360 appliances. Two 

Private Listener 

IronPort Email 

Security appliance

Public Listener 

Internet:

Hosts:        Many
Recipients: Limited

Internal Network:

Hosts:         Limited
Recipients: Many