RE: Steve Landess postings marked as spam -- MIDRANGE-L

Greetings,
Once upon time people from one company using an AS400 for mail, could not
send any to me.  I never saw it. They said they sent it, in fact they put a
copy to my yahoo account and I got it there.  As it turned out that their
AS400 was considered to be an open mail relay.  Spammers love these because
it will make it seem like the AS400 is sending mail and not a spammer.  A
PTF was applied to correct part of the problem.  The second part has to do
with a listing.  There are some sites that you can subscribe to that will
tell you if the mail is from a spammer.  If you are on the list, no mail is
delivered.  I use http://www.dnsstuff.com for all kinds of stuff.  One box
is a spammer database lookup.  If the sending site is listed then the mail
may not get through.  This AS400 site was indeed listed.  We sent some nice
emails to the owners of the list, explained what happened and all is now
right with the world.  Maybe Steve is sending from a valid place, but for
some reason is on the list.

John

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Scott Klement
Sent: Friday, April 08, 2005 2:57 PM
To: Midrange Systems Technical Discussion
Subject: Re: Steve Landess postings marked as spam

Hi Tim,

> The tech people at '1and1' have indicated that these emails are marked as
> spam because they have an incomplete header, i.e. it does not contain a
> valid DNS record entry.

I looked in my mailbox for a message from Steve Landess so I could see the
headers on it.  I assume that the headers from midrange.com forward are
correct (since otherwise you'd have problems with every single message on
the list)

Therefore, here are the headers that we're interested in:

   Received: from hotmail.com (bay103-dav11.bay103.hotmail.com
     [65.54.174.83]) by mail.midrange.com (8.13.1/8.13.1) with ESMTP id
     j35Gr25e008525 for <midrange-l@xxxxxxxxxxxx>; Tue, 5 Apr 2005 11:53:07
     -0500
   Received: from mail pickup service by hotmail.com with Microsoft
     SMTPSVC; Tue, 5 Apr 2005 09:53:01 -0700
   Message-ID: <BAY103-DAV11F1A60DF25B8876E89925853C0@xxxxxxx>
   Received: from 65.54.174.200 by BAY103-DAV11.phx.gbl with DAV;
     Tue, 05 Apr 2005 16:53:00 +0000

You have to start reading at the bottom and work your way up.  Therefore,
look at the "Received" header. It says that an SMTP server running on a
computer called BAY103-DAV11.phx.gbl received the message from
IP address 65.54.174.200.

A DNS lookup on 65.54.174.200 fails -- there's no reverse DNS associated
with that host.Likewise, bay103-dav11.phx.gbl fails it's DNS lookup.
There's no IP address associated with it.

The next Received: record states that the message was received from "mail
pickup service" without logging any specific info about the machine it was
received from.

The final Received: record shows that the message was received by
mail.midrange.com from hotmail.com, and looks completely legitimate.


> (I received this last info second-hand. Is "does not have a reverse DNS
> lookup" the same thing as "a valid DNS record entry"?)

Could be?  "A invalid DNS entry" is a very general, open, error. It could
mean *any* DNS problem.  However "does not have a reverse DNS" would be a
specific problem.


> If we change our spam filter level at '1and1' to medium, these messages
are
> no longer marked as spam, but we then get the opportunity to invest in all
> the new great penny stocks, refinance our mortgages at 3%, and "play all
> night long".

Spam filtering will never be perfect.  There's no way that the computer
will ever be able to know for certain whether e-mail is spam -- at least
until we have computers that are able to think.

In the meantime, they search for particular errors or particular phrases
in the e-mails. If a legitimate message uses them, it'll be marked spam.
If a spam message doesn't use them, it might not be.

The solution for Steve's messages is probably to whitelist him, or to
whitelist everything from midrange.com.  That'll prevent them from being
marked as spam.

The solution to your own e-mail is to look at the headers, find out what
you're doing wrong, and fix it.

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