Cisco Cisco Email Security Appliance X1070 Guía Del Usuario
13-5
User Guide for AsyncOS 9.8 for Cisco Email Security Appliances
Chapter 13 Anti-Spam
IronPort Anti-Spam Filtering
Configuring IronPort Anti-Spam Scanning
Note
When IronPort Anti-Spam is enabled during system setup, it is enabled for the default incoming mail
policy with the default values for the global settings.
policy with the default values for the global settings.
Before You Begin
•
Determine whether you will use regional scanning. See
.
Procedure
Step 1
Select Security Services > IronPort Anti-Spam.
Step 2
If you have not enabled IronPort Anti-Spam 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 Anti-Spam Scanning.
Checking this box enables the feature globally for the appliance.
Step 5
To optimize the throughput of your appliance while still being able to scan increasingly larger messages
sent by spammers, configure the thresholds for message scanning by Cisco Anti-Spam.
sent by spammers, configure the thresholds for message scanning by Cisco Anti-Spam.
Option
Description
Message
Scanning
Thresholds
Scanning
Thresholds
a.
Enter a value for Always scan messages smaller than—The recommended
value is 512 KB or less. Messages smaller than the always scan size will be fully
scanned, except in cases of “early exit.” Messages larger than this size are
partially scanned if they are smaller than the never scan size
value is 512 KB or less. Messages smaller than the always scan size will be fully
scanned, except in cases of “early exit.” Messages larger than this size are
partially scanned if they are smaller than the never scan size
Cisco advises not to exceed 3 MB for the always scan message size. A larger
value may result in decreased performance.
value may result in decreased performance.
b.
Enter a value for Never scan messages larger than—The recommended value
is 1024 KB or less. Messages larger than this size will not be scanned by Cisco
Anti-Spam and the
is 1024 KB or less. Messages larger than this size will not be scanned by Cisco
Anti-Spam and the
X-IronPort-Anti-Spam-Filtered: true
header will not be
added to the message.
Cisco advises not to exceed 10 MB for the never scan message size. A larger
value may result in decreased performance.
value may result in decreased performance.
For messages larger than the always scan size or smaller than the never scan size, a
limited and faster scan is performed.
limited and faster scan is performed.
Note
If the Outbreak Filters maximum message size is greater than Cisco
Anti-Spam’s always scan message, messages smaller than the Outbreak
Filters maximum size are fully scanned.
Anti-Spam’s always scan message, messages smaller than the Outbreak
Filters maximum size are fully scanned.