Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

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Cisco AsyncOS 8.0.2 for Email User Guide

Chapter 9 Using Message Filters to Enforce Email Policies

Attachment Scanning

The following values are recommended:

•

Clean: 0 to 49

•

Suspect: 50 to 74

•

Inappropriate: 75 to 100

You can fine-tune image scanning by configuring the sensitivity setting, which helps reduce the number
of false positives. For example, if you find that you are getting false positives, you can decrease the
sensitivity setting. Or, conversely, if you find that the image scanning is missing inappropriate content,
you may want to set the sensitivity higher. The sensitivity setting is a value between 0 (no sensitivity)
and 100 (highly sensitive). The default sensitivity setting of 65 is recommended.

Tuning Image Analysis Settings

Procedure

Step 1

Go to Security Services > IronPort Image Analysis.

Step 2

Click Edit Settings.

Figure 9-4

Edit IronPort Image Analysis Settings

Step 3

Configure the settings for image analysis sensitivity. The default sensitivity setting of 65 is
recommended.

Step 4

Configure the settings for Clean, Suspect, and Inappropriate verdicts.

When you configure the value ranges, ensure that you do not overlap values and that you use whole
integers.

Step 5

Optionally, configure AsyncOS to bypass scanning images that do not meet a minimum size requirement
(recommended). By default, this setting is configured for 100 pixels. Scanning images that are smaller
than 100 pixels can sometimes result in false positives.