[SpamCop-List] Re: Why Am I Blocked? FAQ

[Frank Ellermann]

Michael Lefevre wrote:

>> I suppose the spamcop bl is not considered a DNSBL because
>> it is supposed to tag email.

That's an idea for the B in blAck vs. blOck.  The SCBL can be
too aggressive for big ISPs as a blOck-list.  But even if it's
"only" used as blAck list to tag mail, it's still a "DNSBL".

> the DNS part refers to the way that the lookups to the list
> are made, so it is a "DNSBL".

One definition of "DNSBL".  Another (less popular) definition
is "DNSBL" for BLs with IPs, and "RHSBL" for BLs of domain
names (RHS = right hand side of mail addresses, behind the @).

In that sense the remaining RFCI-lists are "RHSBLs".  If you
want to test what.ever at some.domain.example against a "RHSBL"
like postmaster.rfc-ignorant.org, then you would ask for the
name some.domain.example.postmaster.rfc-ignorant.org

If you get an answer like 127.0.0.2 then some.domain.example
is listed as ignorant postmaster.   Technically the "host"
some.domain.example.postmaster.rfc-ignorant.org has the "IP"
127.0.0.2.  In practice everybody knows that that's no real
"host" and no Internet "IP", it's a code meaning "listed".

For IPs like 11.22.33.44 and a DNSBL like bl.spamcop.net it's
very similar, the only difference is to use the reverse IP in
the query for "host" 44.33.22.11.bl.spamcop.net - and if that
"host" has an "IP" like 127.0.0.2 then it's listed, i.e. the
original IP 11.22.33.44 somehow made it on this black list.

The command line tool "host" can be used to check BLs.  Most
BLs offer a test entry 127.0.0.2, it's always "listed".  The
command `host 2.0.0.127.bl.spamcop.net` would report:
host 2.0.0.127.bl.spamcop.net = 127.0.0.2

Some servers offer a Web interface for DNS queries.  I like
<http://vweb.nass.com.au/cgi-bin/dnslookup> because I have no
"dig" on my box:

<http://vweb.nass.com.au/cgi-bin/dnslookup?data=2.0.0.127.bl.spamcop.net>

> most people (and the SpamCop site) tend to refer to it as the
> SpamCop BL (or even SCBL)

Yes, famous BLs like the SCBL and SURBL have their own acronyms.

> non-technical folks won't gain anything from having DNSBL
> instead of just BL.

As long as they don't say "RBL" (relay), "RHSBL" (RHS), or
even WL (white list), that would be wrong for the SCBL.

                      Bye, Frank