New blacklist: SPFBL

Leonardo from SPFBL shared the following information with me and I thought it would be useful to share it here with folks.

We created a new technology called SPFBL, that is like DNSBL (DNS Blackhole List) but the SPFBL (SPF Blackhole List) receive IP, sender and HELO as parameters at a TCP connection. The SPFBL is a GPL software (documentation is currently available only in Portuguese):

If the message is complained by users, these parameters gain negative points at a reputation system. A lot of Brazilian providers uses this technology and we receive all reputation data from them:

To promote this new technology, we provide a DNSBL service based in SPFBL network reputation. Our DNSBL accept IPv4, IPv6 and domains.

The delist process can be done at this tool:

If listed by bad reputation, the sender must use our feedback system, that runs at SMTP layer:


Noted and respected spam filterer Spamhaus is indicating that they believe the the Protected Sky ( blacklist is "fraudulent." They report that Protected Sky is "an anonymously-run DNSBL service which was pirating [Spamhaus] data and republishing it as its own work." Spamhaus further indicates that Protected Sky doesn't follow DNSBL best practices as indicated in RFC6471.

That, plus the fact that nobody seems to know who runs this blacklist, plus these allegations over data theft, should be enough to give any email administrator pause when considering whether or not to use this blacklist in their mail server configuration.

Status of DEAD

I first blogged about the ANONWHOIS blacklist back in 2010. It was very useful to identify domains were ownership information was cloaked from the public. Why? Because many of us in the anti-spam and security community think that for a domain being used for commercial purposes, it isn't right to hide who the owner is. And this obstruction to transparency is often exploited by bad guys who send spam and malware, to try to make it harder to identify them.

For folks working in the deliverability realm, we used ANONWHOIS to remind clients that it is not a best practice to mask ownership info for a domain name. ISPs who notice this will often consider it suspicious, and services like the Network Abuse Clearinghouse will decline to include your domains in their database.

The ANONWHOIS website recently went offline, somewhere around the start of February, 2017. (The Internet Wayback Machine last shows the ANONWHOIS website up and running on October 2, 2016.)

I was able to contact one of the maintainers of ANONWHOIS and he confirmed for me that they have shut down for good. Sounds like ICANN policy changes over the past few years have made it harder and harder for them to adequately track information necessary to make informed decisions regarding potential entries on their list.

I am sorry to see them go, but I thank them for their six+ years of service to the internet community.

Perhaps a new service will appear to fill the void.