Re: [anti-spam-wg] Domains with MX set to localhost
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To: der Mouse mouse@localhost
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From: Jan Pieter Cornet johnpc@localhost
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Date: Wed, 11 Jan 2006 17:14:25 +0100
On Wed, Jan 11, 2006 at 10:50:38AM -0500, der Mouse wrote:
> >> [...blocking certain spammer domains...]
>
> > We block a domain if:
>
> > . the MX host is "." (following draft-delany-nullmx)
> > . the MX host isn't a FQDN
> > . the MX host has no associated A record at all
> > . the A record of the MX record is localhost, RFC1918, link-local,
> > class D/E, or a limited set of bogons (yes, I'm watching IANA
> > allocations)
>
> How is the second one possible? An MX record isn't capable of
> containing anything *but* a FQDN. (Or does this really mean "MX hosts
> in nonexistent top-level domains"?)
Sorry, my mistake. I meant if the sender domain is not a FQDN.
Which happens frequently enough from badly configured host to warrant
a specific error message.
> As for the third one - do you actually mean "address record", or do you
> specifically not want to talk to people with IPv6-only MX hosts? Or do
> you block only when *all* MX hosts are problematic?
We certainly only block when all MX records are problematic, but I
oversimplified it heavily. We also check for AAAA records and accept
the email if it finds one (even though our mailservers currently don't
speak IPv6).
--
#!perl -wpl # mmfppfmpmmpp mmpffm pmmppfmfpppppfmmmf@localhost
$p=3-2*/[^\W\dmpf_]/i;s.[a-z]{$p}.vec($f=join('',$p-1?chr(sub{$_[0]*9+$_[1]*3+
$_[2]}->(map{/p|f/i+/f/i}split//,$&)+97):qw(m p f)[map{((ord$&)%32-1)/$_%3}(9,
3,1)]),5,1)='`'lt$&;$f.eig; # Jan-Pieter Cornet
