The following article provides step-by-step information on how to configure the settings for the Barracuda NG Firewall´s Spam Filter Client. In order to be able to use this feature, make sure that a Spam Filter Service is introduced at your firewall as described in: How to Configure Services.
The SPAM Filter client’s work process involves the following:
Spam filter client configuration is done through the section Spam Analysis within the Mail Gateway settings (see: How to Configure Content Stripping, Grey Listing, and Blacklists).
- Go to CONFIGURATION > Configuration Tree > Box > Virtual Servers > your virtual server > Assigned Services > Mail-Gateway > Mail Gateway Settings.
- In the left menu, select Content Adaptions.
- Click Lock.
- In the Spam Detection section, set the parameter Enable Spam Analysis to yes.
- Click Edit to open the Advanced Spam Options window.
- Set the appropriate values for the parameters explained in the sections below.
- Click OK.
Click Send Changes and Activate.
MailGW Settings - Spam Analysis
Spam Analyzer IP
This IP address is the Bind IP of the SPAM Filter service (Bind or Additional IP, see below section Configuring the Spam Filter Server). Optionally, you may enter a DNS resolvable host name. The host name can be used to implement load balancing for high traffic scenarios.
Spam Analyzer Port
This value (default: 783) must correspond with the port defined for the SPAM Filter service (Listening Port, see below section Configuring the Spam Filter Server).
Max. Size (MB)
This parameter defines the maximum size an e-mail may need to be processed by the SPAM Filter. If the e-mail exceeds this value (default: 1 MB) it will not traverse the filter mechanism and will be delivered to its recipient without header modification (spam tag) instead.
This parameter defines the maximum duration (default: 60 s) it may take to analyze an e-mail. If the value is exceeded, the e-mail is delivered to its recipient without header modification (spam tag).
Analyze Internal Mails
When set to yes (default: no) mail traffic generated by internal mail domains is also classified.
An e-mail is rejected when it exceeds the threshold configured here. The threshold is calculated from an e-mail’s spam score (resulting from the testing sequences) multiplied by factor 100. To deactivate this parameter, enter a threshold of 0.
Enable Domain Check
This field allows for checking of sender domains. The following options are available:
Domain check failure results in one of the actions configured through parameter Domain Action (see next entry).
This field only has to be configured, if domain checking (see above) has been enabled. Domain check failure results in one of the following actions:
This field takes a list of trusted domains, which should be excluded from spam filtering. This list is consulted before the SPAM Filter is applied. Top-level and sub-domains may be defined (like barracuda.com and *.barracuda.com).
Continue with How to Configure the Spam Filter Service.