rejecting emails by country origin

[am.lists]

I'd like to share a brief encounter with the dark side of GeoIP. I had
a host at a facility where we had so many IP addresses in so many
different blocks, some of them would occasionally return a "RIPE -
Corrupt Country Data" error when we were reverse-lookup'ed as mail
senders. And as it was the case for us, corrupt country data may as
well have listed us as being in Nigeria or North Korea in terms of how
we scored. (If I had written this, I would treat corrupt as a lookup
error, not negatively score it, but then I didn't write it.)

Turns out that our provider would go to ARIN and tag our block as
"reassigned" and show us as the true owner of the IP block. Not that
that's a bad thing, but whatever tool the mail server software on the
remote side was using to query our IP would get that "reassigned" bit
of information about our IP and would choke on that response.

We took this up with our provider, and learned that anytime they
assigned a block larger than 5 IPs to a customer they were compelled
to register the actual owner of that block with ARIN. (I'm not sure if
that was the hosting company's policy or ARIN's.)

We had several blocks, some contiguous (which were registered as
'reassigned') and some that were in small blocks of non-contiguous
ranges. Our solution was to move the mail server over to a block of
IPs that was not listed as reassigned, and that took care of the
problem for us.

I'm not proclaiming tthat all GeoIP lookup services [mis]behave this
way, but you may run into this if you're on a 'reassigned' block of IP
space.

Angelo





On 2/8/07, Res <res at ausics.net> wrote:
> On Fri, 9 Feb 2007, Nerijus Baliunas wrote:
>
> > This might be OT, but milter-greylist (cvs version or the next development version)
> > supports it (it uses GeoIP for this).
>
> GeoIP is dangerous, it's so often been so very very wrong - use this with
> extreme care
>
>
> --
> Cheers
> Res
>
> "We can be Heroes, just for one day" - Davey (Jones) Bowie
>
>
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