One-time Yahoo administrator Derek Balling has announced that the RFC Ignorant blacklist is being shut down. This blacklist has existed since at least late 2001. Its listing criteria including things like not having an "abuse" or "postmaster"address that accepted mail. Listing criteria didn't necessarily overlap with the generally accepted criteria for fighting spam, so my guess is that this blacklist's lack of usefulness as a spam fighting tool had finally diminished past the point of no useful return. As Derek himself says, "the usefulness of a DNSBL is greatly diminished," and of the old hardware running the service, "the value proposition just isn't there."

I blogged about the RFC Ignorant blacklist back in 2006.

Status of DEAD

The "Fiveten" Blacklist ( was a combination anti-spam blacklist run by Carl Byington, publishing under the name of "510 Software Group." This blacklist has been available since at least February, 2001, and it appears to have been retired as of April 2012.

As of late April, 2012, any attempt to look up an entry on the blacklist results in output indicating that "The list is retired. No ip address is listed here." Meaning, the blacklist is no longer in operation.

I had previously written about this blacklist back in October, 2007, and my 2007-2008 DNSBL statistics project data showed that the blacklist may not be suitable for broad production use if one wishes to receive requested email messages. The list has been up and down at various other times, most recently being taken offline for a period in November 2010.

(Hat tip: Word to the Wise)