Cisco Cisco Email Security Appliance C170 Guia Do Utilizador
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Cisco AsyncOS 8.5 for Email User Guide
Chapter 22 Configuring Routing and Delivery Features
Using Global Unsubscribe
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.
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
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.
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
appliance, use the AsyncOS Global Unsubscribe feature. The
appliance, use the 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.
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.
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
sales representative. Global Unsubscribe addresses can be in one of four forms:
sales representative. Global Unsubscribe addresses can be in one of four forms:
Table 22-10
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 (
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 (
particular domain. The syntax is the specific domain, preceded by an
at sign (
@
).