Cisco Cisco Email Security Appliance C160 Mode D'Emploi

The syntax of a filter using the 

url-category-defang 

action is: 

<msg_filter_name>:

if <condition>

{

url-category-defang([‘<category-name1>’,’<category-name2>’,…, ‘<category-name3>’], 

’<url_white_list>’, <unsigned-only>);

}

The syntax of a filter using the 

url-category-proxy-redirect 

action is: 

<msg_filter_name>:

if <condition>

{

url-category-proxy-redirect([‘<category-name1>’,’<category-name2>’,…, 

‘<category-name3>’], ’<url_white_list>’, <unsigned-only>);

}

The No Operation action performs a no-op, or no operation. You can use this action in a message filter 
if you do not want to use any of the other actions such as Notify, Quarantine, or Drop. For example, to 
understand the behavior of a new message filter that you created, you can use the No Operation action. 
After the message filter is operational, you can monitor the behavior of the new message filter using the 
Message Filters report page, and fine-tune the filter to match your requirements.

The following example shows how to use No Operation action in a message filter.

AsyncOS can strip attachments from messages that are inconsistent with your corporate policies, while 
still retaining the ability to deliver the original message. 

You can filter attachments based on their specific file type, fingerprint, or based on the content of the 
attachment. Using the fingerprint to determine the exact type of attachment prevents users from 
renaming a malicious attachment extension (for example, 

.exe

) to a more commonly used extension (for 

example, 

.doc

) in the hope that the renamed file would bypass attachment filters.

When you scan attachments for content, the Stellent attachment scanning engine extracts data from 
attachment files to search for the regular expression. It examines both data and metadata in the 
attachment file. If you scan an Excel or Word document, the attachment scanning engine can also detect 
the following types of embedded files: .exe, .dll, .bmp, .tiff, .pcx, .gif, .jpeg, .png, and Photoshop images.

new_filter_test: if header-repeats ('subject', X, 'incoming') {no-op();}