Cisco Cisco Email Security Appliance C650 Guía Del Usuario
20-6
Cisco AsyncOS 8.5.5 for Email Security User Guide
Chapter 20 Text Resources
Using and Testing the Content Dictionaries Filter Rules
Dictionary Match Filter Rule
The message filter rule named
dictionary-match(<
dictionary_name
>)
(and its counterparts) evaluates
to true if the message body contains any of the regular expressions in the content dictionary named
dictionary_name. If that dictionary does not exist, the rule evaluates to false.
dictionary_name. If that dictionary does not exist, the rule evaluates to false.
Note that the
dictionary-match()
rule functions similarly to the
body-contains()
body scanning rule:
it only scans the body and attachments of messages, and not the headers.
For scanning headers, you can use the appropriate
*-dictionary-match()
-type rule (there are rules for
specific headers, such as
subject-dictionary-match()
and a more generic rule,
header-dictionary-match()
, in which you can specify any header including custom headers). See
“Dictionary Rules” in the “Using Message Filters to Enforce Email Policies” chapter for more
information about dictionary matching.
information about dictionary matching.
In the following example, a new message filter using the
dictionary-match()
rule is created to blind
carbon copy the administrator when the appliance scans a message that contains any words within the
dictionary named “secret_words” (created in the previous example). Note that because of the settings,
only messages that contain the whole word “
dictionary named “secret_words” (created in the previous example). Note that because of the settings,
only messages that contain the whole word “
codename
” matching the case exactly will evaluate to true
for this filter.
In this example, we send the message to the Policy quarantine:
Table 20-1
Message Filter Rules for Content Dictionaries
Rule
Syntax Description
Dictionary Match
dictionary-match(<dictionary
_name>)
Does the message contain a word that
matches all the regular expressions listed in
the named dictionary?
matches all the regular expressions listed in
the named dictionary?
bcc_codenames:
if (dictionary-match ('secret_words'))
{
bcc('administrator@example.com');
}
quarantine_codenames:
if (dictionary-match ('secret_words'))
{
quarantine('Policy');
}