Thanks for visiting! Remember that nowadays, (most) blocklists don't really govern deliverability and inbox placement. Want to learn more about email marketing best practices, email technology, and deliverability troubleshooting? Then you'll want to check out my other site, Spam Resource.

Beware: "Fake" Blocking list at nszones.com

Spamhaus reports that they have "uncovered a fake spam filter company which was pirating and selling DNSBL data stolen from major anti-spam systems including Spamhaus, CBL and SURBL, republishing the stolen data under the name 'nszones.com.'"

Ouch. I guess if you publish a free or easily accessed spam filtering tool, it is inevitable that at some point somebody would try to take the data and repackage it against copyright and against the data owner's wishes.

If you find yourself listed on this blocking list; don't fret. If what Spamhaus says is true (and I have little reason to doubt them), then this list is not really being used to block email. (And should not be used to block email.) Ignore it, stay listed, and eventually they'll move on to easier targets.

If you're a system administrator, DO NOT use any of the DNSBL zones at nszones.com for spam filtering purposes. As its intent may not be above-board, I would have strong concerns about the possibility of listing things only to engender a payment for delisting -- for reasons having nothing to do with spam fighting.

SURBL Announces New Experimental Blocking List

Today, the team behind the SURBL domain blaclists announced a new, experimental blocking list: xs.surbl.org.

As announced on the SURBL-Announce list: "An experimental source of some snowshoe and pill domains is now being published in xs.surbl.org.  SURBL considers this feed to be experimental and would very much welcome feedback about it, particularly about any false positives.  Does anyone know anyone who actually wants to receive snowshoe messages?"

You can read the entire announcement here.

Status of dnsbl.karmasphere.com: SHUTTING DOWN

As messaged to the Karmasphere-Users and Karmasphere-Announce mailing lists, the Karmasphere Reputation Services data feeds are being retired. This means that the associated blocking list(s), including the karmasphere.email-sender.dnsbl.karmasphere.com DNSBL zone, and any other DNSBL/DNSWL zones under karmasphere.com. It is unclear to the author if karmasphere.org is similarly affected.

Karmasphere has indicated that the feed service will be discontinued on November 16, 2009. It's very important that all Karmasphere-using mail administrators remove any Karmasphere-hosted DNSBLs from their configuration before that date, else inbound receipt of legitimate email messages could be delayed or otherwise impacted.

For more information, click on over to Spam Resource to read a copy of the Karmasphere notice.

Status of rbl.cluecentral.net: DEAD

The rbl.cluecentral.net DNSBLs were created in 2001 or 2002 by Sabri Berisha. The goal: To list "all known assigned IPv4 address space, by originating AS and by country. [This is based on] a full routing view is extracted daily from a router in the default free zone. The AS->country mapping is done via the statistics which are being provided by the four RIR's, ARIN, APNIC, LACNIC and RIPE."

Today, the website warns that the rbl.cluecentral.net service is closed. Sabri notes that "[it has become] more and more difficult and time-consuming to maintain a trustworthy list I started to notice more and more errors. The list is no longer of the quality needed to use in a production environment."

The website warns that if DNS queries continue at a high level, the DNS servers are likely to be configured in a way that will cause 100% of inbound mail attempts to be rejected, for all mail servers still using rbl.cluecentral.net. This makes it imperative that you remove any rbl.cluecentral.net zones from your mail server configuration, as soon as possible.

Status of blackholes.us: DEAD

Created by Matthew Evans in 2002, the goal of the blackholes.us site was "to create (yet more) DNS blocklists of spammers, spam supporting ISPs, spamware hosts, dialup networks, and other notorious email abusers originating in the United States." Matthew published many different DNSBL zones, listing various countries, ISPs, netblocks, etc.