At what level of the net does IP address reputation operate? Do the blocklists ban whole ASNs based on some measured volume of spam? More transparency (or mor

At what level of the net does IP address reputation operate? Do the blocklists ban whole ASNs based on some measured volume of spam? More transparency (or more likely, less ignorance on my part) here would be helpful. Can anyone recommend a one stop tool / script for looking oneself up in the reputation services? (And on that note, it is abhorrent that Big Email providers don’t have open reputation databases, or at least ones where I can look myself up.)