Hello,
Yes, those RBL's are scams. That might be too harsh, but they over block and ask for money to get good IP's within spammy ranges delisted / whitelisted. Responsible mail server operators shouldn't use those RBL's because there are too many false positives. I recommend the Spamhaus RBL's, and if you must have more, SORBS has a reasonable delisting policy too.

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