I enabled the IP-in-rDNS filter, so why isn spamdyke blocking connections from servers with rDNS names that contain IP addresses?
The IP-in-rDNS filter requires two things to block a connection: the rDNS name must contain the IP address AND the rDNS name must contain a keyword. For example, consider the following rDNS name: 11.22.33.44.dynamic.example.com Obviously it contains an IP address (11.22.33.44), but that’s not enough to trigger the filter. If the keyword dynamic were supplied, spamdyke would block the connection. However, note that the keyword example would not be matched. This is because example is part of the last two segments of the domain name. spamdyke will not search for keywords there because that would lead to lots of false positives. It is possible to use a domain name as a keyword, if it is prefixed with a dot. For example: .example.com All connections would be blocked where the rDNS name contained the IP address and the name ended in .example.com.
