Surf Control 5.2.4 Benutzerhandbuch

SurfControl RiskFilter - E-mail V5.2.4

Administrator’s Guide

29

Directory Attack is used by questionable sources to gain access to internal e-mail accounts. A directory 
attack not only occupies large amounts of system resource but also, through the acquisition of e-mail 
accounts, creates spam problems for e-mail end users. RiskFilter enables you to control directory attack to 
limit the maximum messages and connections coming from an IP address over a given time period. Use 
the Directory Attack Control screen to configure this.

                                

The Directory Attack Control screen

There are two levels of control within this pane. The first enables you to specify in seconds how often the 
limit on messages is to be applied. The second will apply the same limits but in minutes. Specifying that 
messages are limited by the second gives you greater control than when you limit them by the minute. 

To configure directory attack control:

1

Select Receive Settings > Directory Attack Control from the System Settings tab.

2

Select the Limit number of messages/connections per IP every ... seconds to enable the level 1 
control then set the maximum number of messages, and connections. You can also set how often the 
same message is allowed to pass through RiskFilter.

3

Select the Limit number of messages/connections per IP every ... minutes to enable the level 2 
control then set the maximum number of messages, and connections. You can also set how often the 
same message is allowed to pass through RiskFilter.

4

If you have selected one of the directory attack control options, you can select the Drop Connection 
option and set a percentage. Once the invalid messages/connections exceed this percentage of the 
total number of invalid messages/connections, the connection will be dropped automatically.

5

Click Submit to put the new settings into effect or Reset if you want to cancel the modifications made 
to the current settings.