As of 22 October, we have changed the behaviour of message analyzing.
If a message contains known hosts, discard the message as already listed but reset “deleted”-dates and relist if necessary.
Messages are no longer discarded with a “already listed”. This behaviour was built to save data storage. Data storage is a problem, but we have to live with that even if some cases is automatically solved by our orphan-cleaner (DNSBL-46). So, for each message found as “already listed”, we are incrementing the hostcount. This means that, the more hits from a server the harder rules are applied on the host.
Source: DNSBL-54