Cisco Cisco Email Security Appliance X1070 User Guide
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User Guide for AsyncOS 10.0 for Cisco Email Security Appliances
Chapter 9 Using Message Filters to Enforce Email Policies
Message Filter Actions
Malformed MIME Header Detection Rule
You can use the
malformed-header
rule to detect messages that contain malformed MIME headers.
Message Filter Syntax
<filter_name>: if (malformed-header){<action>;}
Example
The following example shows how to quarantine all the messages with malformed MIME headers:
quarantine_malformed_headers: if (malformed-header)
{
quarantine("Policy");
}
Message Filter Actions
The purpose of message filters is to perform actions on selected messages.
The two types of actions are:
•
Final actions — such as
deliver
,
drop
, and
bounce
— end the processing of a message, and permit
no further processing through subsequent filters.
•
Non-final actions perform an action which permits the message to be processed further.
Non-final message filter actions are cumulative. If a message matches multiple filters where each filter
specifies a different action, then all actions are accumulated and enforced. However, if a message
matches multiple filters specifying the same action, the prior actions are overridden and the final filter
action is enforced.
specifies a different action, then all actions are accumulated and enforced. However, if a message
matches multiple filters specifying the same action, the prior actions are overridden and the final filter
action is enforced.
Related Topics
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•
•
•
Filter Actions Summary Table
Message filters can apply the following actions shown in
to an email message.
Table 9-5
Message Filter Actions
Action Syntax
Description
Alter source host
alt-src-host
Change the source hostname and IP interface (Virtual
Gateway address) to send the message. See
Gateway address) to send the message. See
Alter recipient
alt-rcpt-to
Change a recipient of the message. See
.
Alter mailhost
alt-mailhost
Change the destination mail host for the message. See