Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

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Cisco IronPort AsyncOS 7.6 for Email Advanced Configuration Guide
OL-25137-01
Chapter 2      Configuring Routing and Delivery Features
When you create a “group,” of Virtual Gateway addresses, the good neighbor table settings for Virtual 
Gateway are applied to the group, even if the group consists of 254 IP addresses.
For example, suppose you have created group of 254 outbound IP addresses set up as a group to cycle 
through in a “round-robin” fashion, and suppose the good neighbor table for 
small-isp.com
 is 100 
simultaneous connections for the system and 10 connections for Virtual Gateway addresses. This 
configuration will never open more than 10 connections total for all 254 IP addresses in that group; the 
group is treated as a single Virtual Gateway address.
Using Global Unsubscribe
To ensure that specific recipients, recipient domains, or IP addresses never receive messages from the 
Cisco IronPort appliance, use the Cisco IronPort AsyncOS Global Unsubscribe feature. The 
unsubscribe
 command allows you to add and delete addresses to a global unsubscribe list, as well as 
enable and disable the feature. AsyncOS checks all recipient addresses against a list of “globally 
unsubscribed” users, domains, email addresses, and IP addresses. If a recipient matches an address in 
the list, the recipient is either dropped or hard bounced, and the Global Unsubscribe (GUS) counter is 
incremented. (Log files will note whether a matching recipient was dropped or hard bounced.) The GUS 
check occurs immediately before an attempt to send email to a recipient, thus inspecting all messages 
sent by the system.
Note
Global Unsubscribe is not intended to replace the removal of names and general maintenance of mailing 
lists. The feature is intended to act as a fail-safe mechanism to ensure email does not get delivered to 
inappropriate entities.
The global unsubscribe feature applies to private and public listeners. 
Global Unsubscribe has a maximum limit of 10,000 addresses. To increase this limit, contact your Cisco 
IronPort sales representative. Global Unsubscribe addresses can be in one of four forms:
Table 2-10
Global Unsubscribe Syntax  
username@example.com
Fully-formed email address
This syntax is used to block a specific recipient at a specific domain.
username@
Username
The username syntax will block all recipients with the specified 
username at all domains. The syntax is the username followed by an 
at sign (
@
). 
@example.com
Domain
The domain syntax is used to block all recipients destined for a 
particular domain. The syntax is the specific domain, preceded by an 
at sign (
@
).