Hi All, SURBL is looking for statistics about what portion of unsolicited our lists are detecting (ideally in large mail flows). An overall number would be ideal, as in what fraction of total unsolicited messages are caught by any SURBL list. One possible way to measure this from SpamAssassin-processed messages would be to count the messages marked as spam that had 'SURBL' in their scores versus the ones that didn't have a SURBL rule hit. The ratio would be the spams with SURBL hits divided by total number of spams.
Another way would be to count the SURBL hits from an MTA milter, but to have the meaningful denominator, one would need a count of the total spams, which a simple SURBL-only milter would not be able to provide. Something else, or a more sophisticated milter would need to count the total spams in order to get the denominator.
Ideally the results would be after MTA blocking with a major sender blacklist like zen.spamhaus.org. Please let us know whether a sender blacklist is used in the MTA or not.
Any results would be greatly appreciated.
Cheers,
Jeff C.