If I have posted this to the wrong forum, I apologize! I am not sure where this should go. First let me say I am not very good with sendmail, so I am sure I have something configured wrong. I run our own mail server and forward my email to spamcop. However I have one type of email that has a problem being deliverd. Any advice is welcomed. Below is the header and email. What does the "552 sorry, your envelope sender domain must exist really mean? Thanks

Received: from majure.majure.com (majure.majure.com [204.1.0.3]) by saturn.majure.com with ESMTP (8.7.1/8.7.1) id LAA12880 for <root[at]saturn.majure.com>; Thu, 29 Apr 2004 11:05:03 -0400 (EDT)
Received: from localhost (localhost)
by majure.majure.com (8.9.3 (PHNE_25183)/8.9.3) with internal id LAA21264;
Thu, 29 Apr 2004 11:05:03 -0400 (EDT)
Date: Thu, 29 Apr 2004 11:05:03 -0400 (EDT)
From: Mail Delivery Subsystem <MAILER-DAEMON[at]majure.com>
Message-Id: <200404291505.LAA21264[at]majure.majure.com>
To: root[at]saturn.majure.com
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="LAA21264.1083251103/majure.majure.com"
Subject: Returned mail: Service unavailable
Auto-Submitted: auto-generated (failure)

This is a MIME-encapsulated message

--LAA21264.1083251103/majure.majure.com

The original message was received at Thu, 29 Apr 2004 11:05:02 -0400 (EDT)
from daemon[at]localhost

----- The following addresses had permanent fatal errors -----
mdi_rd[at]spamcop.net

----- Transcript of session follows -----
... while talking to mx.cesmail.net.:
>>> MAIL From:<root[at]saturn.majure.com> SIZE=199
<<< 552 sorry, your envelope sender domain must exist (#5.7.1)
554 Service unavailable

--LAA21264.1083251103/majure.majure.com
Content-Type: message/delivery-status

Reporting-MTA: dns; majure.majure.com
Arrival-Date: Thu, 29 Apr 2004 11:05:02 -0400 (EDT)

Final-Recipient: RFC822; mdi_rd[at]spamcop.net
Action: failed
Status: 5.3.4
Remote-MTA: DNS; mx.cesmail.net
Diagnostic-Code: SMTP; 552 sorry, your envelope sender domain must exist (#5.7.1)
Last-Attempt-Date: Thu, 29 Apr 2004 11:05:03 -0400 (EDT)

--LAA21264.1083251103/majure.majure.com
Content-Type: text/rfc822-headers

Return-Path: <root[at]saturn.majure.com>
Received: (from daemon[at]localhost)
by majure.majure.com (8.9.3 (PHNE_25183)/8.9.3) id LAA21262
for mdi_rd[at]spamcop.net; Thu, 29 Apr 2004 11:05:02 -0400 (EDT)
Received: from saturn.majure.com (saturn.majure.com [204.1.0.4])
by majure.majure.com (8.9.3 (PHNE_25183)/8.9.3) with ESMTP id LAA21259
for <rd[at]majure.majure.com>; Thu, 29 Apr 2004 11:05:01 -0400 (EDT)
Received: (from root[at]localhost) by saturn.majure.com (8.7.1/8.7.1) id LAA12866 for rd; Thu, 29 Apr 2004 11:05:00 -0400 (EDT)
Date: Thu, 29 Apr 2004 11:05:00 -0400 (EDT)
From: "root[at]saturn" <root[at]saturn.majure.com>
Message-Id: <200404291505.LAA12866[at]saturn.majure.com>
To: rd[at]saturn.majure.com
Subject: su rd-root
Mime-Version: 1.0
Content-Type: text/plain; charset=X-roman8
Content-Transfer-Encoding: 7bit

--LAA21264.1083251103/majure.majure.com--

I am no expert in this field either.

The way I read it, your server is telling spamcop that the sender is root[at]saturn.majure.com. Spamcop checks the domain of that sender (saturn.majure.com) and gets a failure. I also can not resolve saturn.majure.com. Without at least a valid domain, spamcop knows that any messages to that address will bounce, so it rejects the message immediately.

Either your host needs to resolve to an IP address on the internet or you should be relaying all your messages through another server and not sending direct to MX.

Which is a fancy way of saying: Change your mail server to send messages out using the domain name "majure.com", not "saturn.majure.com". The former has an MX record, the latter does not.

Thanks for the input! It got my thinking going in the right direction. I got it working (I think) by masquerading instead of relaying. I like the idea of not having any relays open if you know what I mean

Can anyone tell me how to do this on a cpanel server please?
thanks in advance.