It actually gets worse!
I finally figured out what has been crashing my machine for the past few
days... and it's related to this bug i think.

To reproduce:

Create a moderated mailing list. eg <email address hidden>
Send a mail from your mailman user (eg su to mailman id and type:

echo "test" | mail -s "test" <email address hidden>        
 (where <email address hidden> is your moderated mailing list))

The mail gets sent to the mailing list and held for approval
(<email address hidden> isn't a subscriber).  A 
message gets sent back to <email address hidden> saying the message is held
for approval (which mailman 
tries to post to the mailman list).

At this stage stuff starts to stop working on the machine (smtp, telnet
and syslogd mainly).  What I've got from 
stracing syslogd (I originally thought it was a syslogd problem) and a
mail from root are below:

The thing is not that mailman is going to be sending mails to lists
locally, but more someone could spoof a mail 
and DOS your machine. not nice!!!  From what I've seen (evidence below) -
there isn't a fight between the two lists 0 
but i may be wrong.

Quick fix: set "respond_to_post_requests" to No.

System info: Suse Linux 7.0, Syslogd 1.3-3, Mailman 2.1b (cvs - may 9th)

If this has been fixed already or is a seperate bug I apologise in advance
for the long comment.

-----------------------------------------------------------------------------------------------
<email address hidden>: Command died with status 1:
    "/usr/local/mailman/mail/wrapper post mailman"




Reporting-MTA: dns; hostname.dcu.ie
Arrival-Date: Wed, 22 May 2002 16:02:45 +0100 (IST)

Final-Recipient: rfc822; <email address hidden>
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; Command died with status 1:
    "/usr/local/mailman/mail/wrapper post mailman"




Received: from hostname.dcu.ie (localhost [127.0.0.1])
        by hostname.dcu.ie (Postfix) with ESMTP id DB02D5DFEA
        for <email address hidden>; Wed, 22 May 2002 16:02:45
+0100 (IST)
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: Your message to Test2 awaits moderator approval
From: <email address hidden>
To: <email address hidden>
Message-ID: <email address hidden>
Date: Wed, 22 May 2002 16:02:44 +0100
X-BeenThere: <email address hidden>
X-Mailman-Version: 2.1b2+
Precedence: bulk
List-Id: <test2.hostname.dcu.ie>
X-List-Administrivia: yes
Sender: <email address hidden>
Errors-To: <email address hidden>
-----------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------
writev(1, [{"May 22 02:36:40", 15}, {" ", 1},
{"hostname", 7}, {" ", 1}, {"local[6728]: fatal:
execvp /usr/"..., 85}, {"\r\n", 
2}], 6) = ?ERESTARTSYS (To be restarted)
--- SIGALRM (Alarm clock) ---
time(NULL)                              = 1022032087
rt_sigaction(SIGALRM, {0x405304, [], SA_RESTART}, {0x405304, [],
SA_RESTART}, 8) = 0
alarm(30)                               = 0
sigreturn()                             = ? (mask now [])
writev(1, [{"May 22 02:36:40", 15}, {" ", 1},
{"hostname", 7}, {" ", 1},{"local[6728]: fatal:
execvp /usr/"..., 85}, {"\r\n", 
2}], 6) = ?ERESTARTSYS (To be restarted)
--- SIGALRM (Alarm clock) ---
time(NULL)                              = 1022032117
rt_sigaction(SIGALRM, {0x405304, [], SA_RESTART}, {0x405304,
[],SA_RESTART}, 8) = 0
alarm(30)                               = 0
sigreturn()                             = ? (mask now [])
writev(1, [{"May 22 02:36:40", 15}, {" ", 1},
{"linux28", 7}, {" ", 1},
{"local[6728]: fatal: execvp /usr/"..., 85}, {"\r\n",
2}], 6 <unfinished
-----------------------------------------------------------------------------------------------