Dear Guys,

Would anyone know why after sending a single email to around 12,000 people from various distribution lists they would receive that same email in the region of 30 to 130 times additionally.

We've been going round in circles trying to sort this out and are unable to send a mail with the new system incase this happens again (Possible legal action threats have been expressed already as a result of last weeks blunder)

The setup is as follows:

Windows 2003 Server (Service Packed and Patched to date)
Office Outlook 2003 (Same as above)

Behind a router so no firewall is installed, no antivirus is installed either, thus emails arnt scanned on the way out (or being duplicated for that matter) (Yes i know im asking for trouble here however the less variables in the sum the less to go wrong)

We have around 7 distribution lists, the main contains around 12,000 clients the others are around 1,000 max each.

Weve checked on where the mail is coming from and it all resolves back to our hosts mail server which we use for the sending of the mails.

Is it possible for someone to have slipped us a rogue email address that once it receives our mailshot it then resends this out spoofing its origin??? (Note: We Bcc'd all the clients so people shouldnt be able to see who it was meant to go out to)

As far as im aware the hosts mail server is using visnetic mail server however i havent verifiend this just yet.

The following is a snippet of one of the emails headers (some items are blanked out for obvious reasons)

xxxxxxxxxx = Censored

This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
(generated from xxxxxxxxxx)
mailbox is full
------ This is a copy of the message, including all the headers. ------
Return-path: <xxxxxxxxxx>
Received: from [] (
by with esmtp (Exim 4.34)
id 1FjQXs-0003ki-Hv
for xxxxxxxxxx; Fri, 26 May 2006 01:51:17 +0100
Received: from LBSMAILSERVER ([[/I][EMAIL=""][I]xxxxxxxxxx[/I][/EMAIL][I]])
by (VisNetic.MailServer.v7.2.4.0) with ASMTP id KNC37895;
Fri, 26 May 2006 01:26:10 +0100
Return-Receipt-To: "LBS Sales" <xxxxxxxxxx>
Reply-To: <xxxxxxxxxx>
From: "LBS Sales" <xxxxxxxxxx>
To: <xxxxxxxxxx>
Subject: Stock 25th May
Date: Sun, 10 Mar 2002 01:14:09 -0000
Organization: Living Business Solutions LTD
Message-ID: <xxxxxxxxxx>
MIME-Version: 1.0
Content-Type: multipart/related;
X-Mailer: Microsoft Office Outlook 11
Thread-Index: AcHHg6TzSYzY5GWhTCOIJt2N/v+qAA==
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.2663
Disposition-Notification-To: "LBS Sales" <xxxxxxxxxx>

This reply is for a full mailbox so it might not help here however it's worth a shot.

Any help regarding this issue would be great as im tearing out whats left of my hair.


P Davidson

I've had the same issue with my Exchange 2003 server. My users send an email with many recipients in the BCC filed, nothing in the To field. Some recipients complained of multiple copies. We tried using both a smart host and using DNS - same problem.

In my previous position I came across the issue from the recipients point of view - their SBS Exchange 2003 needed the POP3 connector patch to fix the problem.

Any ideas?

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, learning, and sharing knowledge.