This filter performs a SenderScore lookup and allows OpenSMTPD to either block or slow down a session based on the reputation of the source IP address.

The filter currently supports: * blocking hosts with reputation below a certain value * adding an X-SenderScore header with the score of the source IP address * adding an X-Spam header to hosts with reputation below a certain value * applying a time penalty proportional to the IP reputation * whitelisting IP addresses or subnets