[RFCI-Discuss] Re: .NU considered harmful

[Jeff Makey]

Derek wrote:
>If you can get me a complete list of *.NU domains, that *might* be 
>possible, because otherwise, there would be false claims being made 
>against the many (valid-to-DSN) .NU domains.

The best way to get a list of valid .NU domains would be to transfer
the zone from one of the authoritative DNS servers, but they probably
have that disabled.  The transfers would have to be done regularly to
keep up with what I assume are frequent changes to the set of
registered .NU domains, which would not be a happy way for RFCI to
operate.

>Otherwise, though, it's a crappy problem with no real easy solution...

It doesn't stop there.  This type of problem suggests other more ironic
methods of abuse, in that sendmail and perhaps other MTAs will accept
such gems as these:

  nobody@test.com.dsn.rfc-ignorant.org
  nobody@any.random.subdomain.test.com.abuse.rfc-ignorant.org

as valid senders.  Until MTAs can be enhanced to reject sender domains
by the IP address they resolve to, it may be appropriate to include all
of the blacklist zones in the dsn and postmaster lists with wildcards.
My blacklist survey at http://www.sdsc.edu/~jeff/spam/cbc.html has a
fairly complete list of zones.

                          :: Jeff Makey
                             jeff@sdsc.edu