Cisco Cisco Email Security Appliance C160 Mode D'Emploi
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User Guide for AsyncOS 9.8 for Cisco Email Security Appliances
Chapter 9 Using Message Filters to Enforce Email Policies
Message Filter Actions
Note
Attachment-based rules (for example,
attachment-contains
) or actions (for example,
drop-attachments-where-contains
) will not work on malformed messages (with duplicate MIME
boundaries).
Message Filter Syntax
<filter_name>: if (duplicate_boundaries){<action>;}
Example
The following message filter will quarantine all the messages that contain duplicate MIME boundaries.
DuplicateBoundaries: if (duplicate_boundaries) { 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
•
•
•
•
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