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IronPort - advanced configuration guide

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Chapter 6 Using Message Filters to Enforce Email Policies<br />

Subject Rule<br />

OL-25137-01<br />

The subject rule selects those messages where the value of the subject header matches the given regular<br />

expression.<br />

For example, the following filter discards all messages with subjects that start with the phrase Make<br />

Money...<br />

You can specify non-ASCII characters to search for in the value of the header.<br />

When working with headers, remember that the current value of the header includes changes made<br />

during processing (such as with filter actions that add, remove, or modify message headings). See<br />

Message Header Rules and Evaluation, page 6-4 for more information.<br />

The following filter returns true if the headers are empty or if the headers are missing from the message:<br />

Note This filter returns true for empty Subject and To headers, but it also returns true for missing headers. If<br />

the message does not contain the specified headers, the filter still returns true.<br />

Envelope Recipient Rule<br />

}<br />

scamFilter:<br />

drop();<br />

if (subject == '^Make Money')<br />

{<br />

}<br />

drop();<br />

EmptySubject_To_filter:<br />

if (header('Subject') != ".") OR<br />

}<br />

(header('To') != ".") {<br />

drop();<br />

The rcpt-to rule selects those messages where any Envelope Recipient matches the given regular<br />

expression. For example, the following filter drops all messages sent with an email address containing<br />

the string “scarface.”<br />

Cisco <strong>IronPort</strong> AsyncOS 7.6 for Email Advanced Configuration Guide<br />

6-21

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