Fwd: Returned mail: User unknown

Hi Gord.... here is what I get if I hit REPLY to a post on the list...

However, If I use this address:

Mark I. Nelson
www.MarkINelsonPhoto.com
www.PrecisionDigitalNegatives.com
PDNPrint Forum @ Yahoo Groups

Return-path: <>
Received: from rly-xb01.mx.aol.com (rly-xb01.mail.aol.com [172.20.64.47])
 by air-xb04.mail.aol.com (vx) with ESMTP id MAILINXB41-8a43e1034a36d; Wed,
 01 Feb 2006 13:51:59 -0500
Received: from imo-d03.mx.aol.com (imo-d03.mx.aol.com [205.188.157.35])
 by rly-xb01.mx.aol.com (vx) with ESMTP id MAILRELAYINXB18-8a43e1034a36d; Wed,
 01 Feb 2006 13:51:54 -0500
Received: from localhost (localhost)
          by imo-d03.mx.aol.com (8.8.8/8.8.8/AOL-5.0.0) with internal id NAA09280;
 Wed, 1 Feb 2006 13:51:54 -0500 (EST)
Date: Wed, 1 Feb 2006 13:51:54 -0500 (EST)
From: Mail Delivery Subsystem <MAILER-DAEMON@aol.com>
Subject: Returned mail: User unknown
To: Ender100@aol.com
Message-id: <200602011851.NAA09280@imo-d03.mx.aol.com>
Auto-submitted: auto-generated (failure)
MIME-version: 1.0
X-Mailer: Unknown (No Version)
Content-type: multipart/report;
 boundary="Boundary_(ID_Q4Ih/ikcOuCsTdWL2MH7Jg)"; report-type=delivery-status
X-AOL-IP: 205.188.157.35

--Boundary_(ID_Q4Ih/ikcOuCsTdWL2MH7Jg)

The original message was received at Wed, 1 Feb 2006 13:51:42 -0500 (EST)
from root@localhost

*** ATTENTION ***

Your e-mail is being returned to you because there was a problem with its
delivery. The address which was undeliverable is listed in the section
labeled: "----- The following addresses had permanent fatal errors -----".

The reason your mail is being returned to you is listed in the section
labeled: "----- Transcript of Session Follows -----".

The line beginning with "<<<" describes the specific reason your e-mail could
not be delivered. The next line contains a second error message which is a
general translation for other e-mail servers.

Please direct further questions regarding this message to the e-mail
administrator or Postmaster at that destination.

--AOL Postmaster

   ----- The following addresses had permanent fatal errors -----
<alt-photo-process-l@sask.usask.ca>

   ----- Transcript of session follows -----
... while talking to spamf3.usask.ca.:
>>> RCPT To:<alt-photo-process-l@skyway.usask.ca>
<<< 550 <alt-photo-process-l@skyway.usask.ca>: Recipient address rejected: User unknown in relay recipient table
550 <alt-photo-process-l@sask.usask.ca>... User unknown

--Boundary_(ID_Q4Ih/ikcOuCsTdWL2MH7Jg)
Arrival-date: Wed, 1 Feb 2006 13:51:42 -0500 (EST)
Reporting-MTA: dns; imo-d03.mx.aol.com

Final-Recipient: RFC822; alt-photo-process-l@skyway.usask.ca
Action: failed
Status: 5.1.1
Remote-MTA: DNS; spamf3.usask.ca
Diagnostic-Code: SMTP; 550 <alt-photo-process-l@skyway.usask.ca>: Recipient address rejected: User unknown in relay recipient table
Last-Attempt-Date: Wed, 1 Feb 2006 13:51:54 -0500 (EST)

--Boundary_(ID_Q4Ih/ikcOuCsTdWL2MH7Jg)
Content-type: text/rfc822-headers

Received: from Ender100@aol.com
    by imo-d03.mx.aol.com (mail_out_v38_r6.3.) id z.190.5073e44c (63000)
     for <alt-photo-process-l@sask.usask.ca>; Wed, 1 Feb 2006 13:51:42 -0500 (EST)
Return-path: <Ender100@aol.com>
From: Ender100@aol.com
Message-ID: <190.5073e44c.31125d3e@aol.com>
Date: Wed, 1 Feb 2006 13:51:42 EST
Subject: Re: posting problems
To: alt-photo-process-l@sask.usask.ca
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="part1_190.5073e44c.31125d3e_boundary"
X-Mailer: Thunderbird - Mac OS X sub 208
X-Spam-Flag: YES

--Boundary_(ID_Q4Ih/ikcOuCsTdWL2MH7Jg)--
Received on Wed Feb 1 12:53:42 2006