[March 2, 2017]
We’ve been receiving a high number of complaints lately, about rfc-clueless.org and the fact that their website shows some domains/hostnames as not blacklisted, while our platform shows them as blacklisted.
Our platform queries these blacklists, like any email server does, via DNS queries, and the DNS queries show the checked domains/hostnames as being blacklisted by this RBL, even though their website says otherwise.
A simple way of checking this is to run in any linux terminal the following command:
dig @8.8.8.8 YOURDOMAIN.fulldom.rfc-clueless.org A +short
If the response is ‘127.0.0.1’ then your domain/hostname is blacklisted, regardless of what their website says.
Usually, the root cause of such issues is when their website data is not in sync with their nameservers data, thus giving out different results.
Considering that we have no affiliation with this blacklist, we cannot say if or when this issue will be resolved on their side.
For now we’re leaving this RBL active in our system, since it would appear the false positives only appear to be affecting their website, and not the actual DNS queries.