The drilldown feature allows GBUdb to automatically learn to ignore IPs as infrastructure by matching message source candidates in received headers with specific patterns.

The <drilldown> section of the configuration file contains a list of pattern definitions that describe received headers that will contain IPs that should be ignored. Each pattern is represented by a <received/> entry.

With the drilldown feature, you can Ignore IP Blocks and Ignore Friendly Servers by Reverse DNS.