Google Message Security for Google Apps Administration Guide - Manual (Page 238)

238 Message Security for Google Apps Administration Guide
To create a custom filter that deletes other null-sender messages:
1. Under Rules, set Match to: Any Rule.
2. Set the first rule in the filter to:
• Select Location: Sender
• Select Filter Type: is empty
3. Set Routing to: Delete (Blackhole).
4. If you want to copy the deleted messages to one or more quarantines, you
can set Copy to Quarantine to the appropriate value.
To set priority for the two null-sender filters:
In order for these filters to work together properly, you need to give the first rule
(allow valid null-sender messages) priority over the second rule (delete other null-
sender messages).
For instructions on setting filter priority, see “Reorder Content Filters and Policies”
on page 216.
Test Content Filters First
Before actually deploying a new content filter, you can test its effectiveness first.
Testing your filters first can also help you to prevent deploying filters that capture
too many legitimate messages.
To test a content filter:
1. When creating the filter, select a message disposition of either BCC-
Quarantine or Log and Deliver. Neither of these dispositions prevent
messages from being delivered.
2. After a period of time, create a Filter Name report to determine how many
messages the filter captured. For example, you can determine the daily catch
rate for your filter, by creating a new report each day.
For details about the Filter Name report, see “Filter Name (Inbound,
Outbound)” on page 344.
Troubleshoot Content Manager
I created a content filter rule with a full file name for the value and a location of
Entire Message. However, the filter didn’t capture a message that contained an
attachment with that file name. Why?
Content Manager does not scan the file name of attached files. Some email
programs include the names of attached files in the headers. If the file name does
not appear there, Content Manager won’t capture the message.