This solution applies to all Barracuda Web Filters, firmware 4.0 or higher
The custom category will consider the domain name as listed when evaluating policy. A subdomain will also be considered as part of the parent domain name listing as long as the subdomain is not explicitly included in a Barracuda Web Filter standard category. In such cases where a subdomain should override its standard categorization the subdomain should be listed explicitly in the custom category.
If domain.com is listed in a custom category, mail.domain.com will not be considered part of the listing since it already belongs to the Web-based Email standard category. However, xxx.domain.com will be considered part of the domain.com listing in the custom category because is not already included in a standard category.
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