Someone has to maintain the blacklist, I don't think it matters whether they do so using free software or not. The other issue, not raised by this article (pro

Someone has to maintain the blacklist, I don't think it matters whether they do so using free software or not. The other issue, not raised by this article (probably because the author hasn't hit that problem yet) is that some providers like gmail seem to flag things as spam just because the sending server is unknown. At least, I have mail being put into spam folders for gmail users even though my servers are on no blacklists. And no, I don't make a habit of sending enticing offers for "FREE V1agr4!!1"