Cisco Cisco Email Security Appliance C650 Guía Del Usuario
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Cisco AsyncOS 8.5.5 for Email Security User Guide
Chapter 13 Anti-Spam
Cisco Intelligent Multi-Scan Filtering
Cisco
Intelligent Multi-Scan Filtering
Cisco Intelligent Multi-Scan incorporates multiple anti-spam scanning engines, including Cisco
Anti-Spam, to provide a multi-layer anti-spam solution.
Anti-Spam, to provide a multi-layer anti-spam solution.
When processed by Cisco Intelligent Multi-Scan:
•
A message is first scanned by third-party anti-spam engines.
•
Cisco Intelligent Multi-Scan then passes the message and the verdicts of the third-party engines to
Cisco Anti-Spam, which assumes responsibility for the final verdict.
Cisco Anti-Spam, which assumes responsibility for the final verdict.
•
After Cisco Anti-Spam performs its scan, it returns a combined multi-scan score to AsyncOS.
•
Combining the benefits of the third-party scanning engines and Cisco Anti-Spam results in more
caught spam while maintaining Cisco Anti-Spam’s low false positive rate.
caught spam while maintaining Cisco Anti-Spam’s low false positive rate.
You cannot configure the order of the scanning engines used in Cisco Intelligent Multi-Scan; Cisco
Anti-Spam will always be the last to scan a message and Cisco Intelligent Multi-Scan will not skip it if
a third-party engine determines that a message is spam.
Anti-Spam will always be the last to scan a message and Cisco Intelligent Multi-Scan will not skip it if
a third-party engine determines that a message is spam.
Using Cisco Intelligent Multi-Scan can lead to reduced system throughput. Please contact your Cisco
support representative for more information.
support representative for more information.
Note
The Intelligent Multi-Scan feature key also enables Cisco Anti-Spam on the appliance, giving you the
option of enabling either Cisco Intelligent MultiScan or Cisco Anti-Spam for a mail policy.
option of enabling either Cisco Intelligent MultiScan or Cisco Anti-Spam for a mail policy.
Configuring Cisco Intelligent Multi-Scan
Note
When Cisco Intelligent Multi-Scan is enabled during system setup, it is enabled for the default incoming
mail policy with the default values for the global settings.
mail policy with the default values for the global settings.
Before You Begin
Activate the feature key for this feature. See
. You will see the IronPort
Intelligent Multi-Scan option only if you have done so.
Procedure
Step 1
Select Security Services > IronPort Intelligent Multi-Scan.
Step 2
If you have not enabled Cisco Intelligent Multi-Scan in the system setup wizard:
a.
Click Enable.
b.
Scroll to the bottom of the license agreement page and click Accept to accept the agreement.
Step 3
Click Edit Global Settings.
Step 4
Select the check box for Enable IronPort Intelligent Multi-Scan.
Checking this box enables the feature globally for the appliance. However, you must still enable
per-recipient settings in Mail Policies.
per-recipient settings in Mail Policies.