there is a whitelist rbl now ironport s bonded sender is basically a whitelist rbl where you post a bond to get on the list and then lose the bond if you end up spamming from that ip address or something like that URL c on sunday august NUMBER NUMBER at NUMBER NUMBER pm bart schaefer wrote NUMBER dnsbl only certifies an ip address not who is using it as it is currently used dnsbl allows you to look up if some ip address has been blacklisted by someone what i haven t seen is a service that provides a dns based whitelist there s a practical reason for that any dns list white or black works only for a limited number of ips the set of unlisted ips is much larger than the set in the dns list if you have to make a binary decision to accept or reject you ll be wrong less often if you reject the blacklist and accept everything else rather than accept the whitelist and reject everything else a whitelist is only helpful when a you only want mail from a limited number of known sources or b you can use a secondary system like sa to decide what to do with the vast unlisted masses most mtas still make only the binary decision because the secondary computation is expensive with sa s cooperation though it might be worth a try even better if one could get commercial anti spam outfits to agree to factor it in this URL email is sponsored by osdn tired of that same old cell phone get a new here for free URL _______________________________________________ spamassassin talk mailing list spamassassin talk URL URL 