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

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.