IronPort - Configuration Guide - AsyncOS 7.6.1

Additional Steps
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Cisco IronPort AsyncOS 7.6 for Email Configuration Guide
Chapter 9 Anti-Spam
Checking this box enables the feature globally for the appliance. However, you must still enable
per-recipient settings in Mail Policies. For more information, see Configuring Per-Recipient Policies for
Anti-Spam, page 9-12
Step 6 Enter a value for the always scan message size for Cisco IronPort Anti-Spam.
The recommended value is 512 Kb or less. Messages smaller than the always scan size will be fully
scanned by CASE, except in cases of “early exit.” Messages larger than this size are partially scanned
by CASE if they are smaller than the never scan size entered in Step 7. See Industry-Leading
Performance, page 9-5 for more information on the “early exit” system.
Note Cisco advises not to exceed 3 MB for the always scan message size. A larger value may result
in decreased performance.
Step 7 Enter a value for the never scan message size.
The recommended value is 1024 Kb or less. Messages larger than this size will not be scanned by Cisco
IronPort Anti-Spam and the X-IronPort-Anti-Spam-Filtered: true header will not be added to the
message.
Note Cisco advises not to exceed 10 MB for the never scan message size. A larger value may result
in decreased performance.
Step 8 Enter the number of seconds to wait for timeout when scanning a message.
When specifying the number of seconds, enter an integer from 1 to 120. The default value is 60 seconds.
Step 9 Enable or disable regional scanning. Regional scanning optimizes Cisco IronPort Anti-Spam scanning
for a particular region. Because this feature optimizes the anti-spam engine for a particular region, it can
reduce capture rates for other types of spam. Therefore, Cisco recommends you enable this feature only
if you receive the bulk of your email from the specified region. For more information about regional
scanning, see International Users, page 9-6.
Step 10 Submit and commit your changes.
The Security Services > IronPort Anti-Spam page is refreshed to display the values you chose in the
previous steps.
Figure 9-6 Cisco IronPort Anti-Spam Global Settings
Once you have enabled Cisco IronPort Anti-Spam, enable SenderBase Reputation Service scoring, even
if you are not rejecting connections based on SenderBase Reputation Scores. For more information on
enabling SBRS, see Implementing SenderBase Reputation Filters, page 7-4.
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