Side-effect involving mailing lists

I'll admit to being a bit lazy in this, so feel welcome to tell me "Read
Your Friendly exim4.conf File" or "Read the Friendly Pipermail Archive"
-- but this might at least be mildly entertaining.

I _love_ sa-exim's teergrubing -- even though there are some unintended
consequences with relayed mail in sundry forms (backup MX, mailing
lists).  

1.  The first couple of days after converting to sa-exim, I realised
I was tarpitting my main backup MX, Richard Couture's myrddin.imat.com: 
Richard clings to an old-school "all mail is sacred" admin philosophy,
was relaying large amounts of spam, and accordingly was getting 
"451 Please try again later" upon attempting redelivery.

When I realised this, I wrote Richard to thank him for years of generous
help and discontinued all backup MX service.  (Speculation:  The notion
of backup MXes will be collateral damage in the spam war:  Unless all your
MXes use the same antispam policy, they'll tend to sanction one another.)  

2.  Similarly, I've noticed my system teergrubing spam-permissive
mailing lists:

   Date: 16 Nov 2003 12:24:59 -0000
   From: [email protected] 
   To: [email protected]
   Subject: ezmlm warning

   Hi! This is the ezmlm program. I'm managing the
   [email protected] mailing list.

   Messages to you seem to have been bouncing. I've attached a copy of 
   the first bounce message I received.

   If this message bounces too, I will send you a probe. If the probe bounces,
   I will remove your address from the mailing list, without further notice.

   I've kept a list of which messages bounced from your address. Copies of
   these messages may be in the archive. To get message 12345 from the
   archive, send an empty note to [email protected].
   Here are the message numbers:

      7365

    --- Below this line is a copy of the bounce message I received.

   Return-Path: <>
   Received: (qmail 30581 invoked for bounce); 4 Nov 2003 17:58:16 -0000
   Date: 4 Nov 2003 17:58:15 -0000
   From: [email protected]
   To: [email protected]
   Subject: failure notice

   Hi. This is the qmail-send program at ns.crynwr.com.
   I'm afraid I wasn't able to deliver your message to the following addresses.
   This is a permanent error; I've given up. Sorry it didn't work out.

   <[email protected]>:
   198.144.195.186 failed after I sent the message.
   Remote host said: 451 Please try again later
   I'm not going to try again; this message has been in the queue too long.


Anyone want to advise DJB of the distinction between SMTP rejects
and "bouncing"?  I'm not volunteering.  ;->

Just to confirm my strong suspicion, I asked EZMLM to send me post
#7365.  Indeed, it's classic 419 scam-spam.  

Separately, Yahoo Groups has put me on "nomail" several times for
"bouncing" [sic] its crappy mailing lists' relayed spam -- though that's
trivial to reverse.


What I'm curious about is:  What's a reasonable way to deal with this
problem?  I'm tempted to label the "problem" serendipitous, and conclude
that spam-permissive listadmins _should_ be teergrubed into oblivion,
but what do people do for spam-permissive mailing lists they want to
read, not get spam from, and not get thrown off on account of teergrubing
them?

-- 
Cheers,                             * Contributing Editor, Linux Gazette *
Rick Moen                       -*- See the Linux Gazette in its new home: -*-
[email protected]                       <http://linuxgazette.net/>