I am on a blacklist but I don't care a bit and my ISP neither
While busy with looking through the listings with Belgian servers in blacklists I found the really strange fact that there are a lot of them blacklisted since a long time and that didn't do anything to have them retired from it.
Do they have any knowledge about what the consequences are for an emaildomein to be blacklisted. It means that your mails will be refused by mailservers all over the world without any notification. For the ISP it means that the IP address is compromised and may not be used by another firm before all complaints and cases about the previous owner are cleaned up.
How would you feel if you would get this IP address from your ISP
and you would find that it is blacklisted since 2005 without any follow up
and this is just one example
You would presume that big ISP's controlled frequently those blacklists to be sure that no server or 'infected' stations were mentioned in those and to clean up or follow up on them. You would also presume that a good admin would look from time to time into blacklists to see if his servers are mentioned.
Just to presever the integrity and value of his domain
Even more because most of these incidents seem to be maldirected open relay tests or single incidents in which it is easy to solve the problem. You may say rightly so that the example is in an unconfirmed list but nonetheless it will be red in many indicators and that may get starting over alarms that aren't necessary.