[ltp] OT: broken mail server setup for linux-thinkpad mailing list

[Henrique de Moraes Holschuh]

On Wed, 05 Oct 2011, Travis Biehn wrote:
> This is fantastically bad :(

Kindly refrain from top-posting.  In fact, don't blind-quote the entire
message instead of properly trimming it either: that is even more
annoying than top-posting.

Anyway, no, it is not fantastically bad, at least not to anyone but Mr.
Steigerwald.  If my systems were rejecting perfectly valid email I
wanted to receive, I'd certainly consider it to be "fantastically
bad"...

> On Wed, Oct 5, 2011 at 1:56 PM, Martin Steigerwald <Martin@lichtvoll.de>wrote:
> > thinkpad. - helo: .parabel.matrix. - helo-domain: .matrix.)  FROM/
> > MX_MATCHES_NOT_HELO(DOMAIN)=2.062 CLIENT_NOT_MX/A_FROM_DOMAIN=5.75
> > CLIENT/24_NOT_MX/A_FROM_DOMAIN=5.75; <client=89.106.220.16> <helo=p
> > arabel.matrix.de> <from=linux@linux-thinkpad.org>

Let's have a look at the outgoing relay of this ML, shall we?

parabel.matrix.de has address 89.106.220.16, and you receive the mail from
89.106.220.16 which claimed an ehlo=parabel.matrix.de.  This is well there
in the "paradise land" of EHLOs: it is a valid fqdn that maps to the public
IP of the sending relay!

Furthermore, the PTR record of 89.106.220.16 maps to something that maps
back to 89.106.220.16.  So, it is a *perfectly well configured host*,
which _has_ a canonical name, and said canonical name properly resolves
to the same host.

89.106.220.16 also has a pristine reputation, and it is not on any RBLs,
not even the more ridiculous ones like the level-2 and level-3
UCEPROTECT.

This ML has a very good and well behaved sending relay.  If your setup
is rejecting mail from it, and you actually intended it to just filter
out spam with a very low false positive ratio, rest assured that your
setup has big problems.

If you didn't lose a lot more good email than just those from this ML
(which you can get from the archives), consider yourself very lucky.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh