backscatter hosts

Steven Champeon schampeo at
Tue May 18 22:54:32 UTC 2004

on Tue, May 18, 2004 at 11:37:49PM +0100, Chris Edwards wrote:
> Much as I hate to come to their defence, hotmail rejects unknown users
> during the dialog, and has done so for as long as I can remember.

That may be so. But I've got 208 hosts "back"listed for
backscatter dreck such as this:

 From MAILER-DAEMON  Wed Apr 14 16:17:33 2004
 Received: from ( [])
    by (8.12.9p1/8.12.8/NO-UCE-NO-UBE-NO-spam) with ESMTP id i3EKHVAh005383
    for <rbghvavo at>; Wed, 14 Apr 2004 16:17:32 -0400
 Received: from ([]) by with Microsoft SMTPSVC(5.0.2195.6713);
      Wed, 14 Apr 2004 13:17:36 -0700
 From: postmaster at
 To: rbghvavo at
 Date: Wed, 14 Apr 2004 13:14:29 -0700
 MIME-Version: 1.0
 Content-Type: multipart/report; report-type=delivery-status;
 Message-ID: <EZF98vvwN00000591 at>
 Subject: Delivery Status Notification (Failure)
 X-OriginalArrivalTime: 14 Apr 2004 20:17:36.0210 (UTC) FILETIME=[86CCFB20:01C4225D]
 Content-Length: 7430
 Lines: 142 

 This is a MIME-formatted message.
 Portions of this message may be unreadable without a MIME-capable mail program.

 Content-Type: text/plain; charset=unicode-1-1-utf-7

 This is an automatically generated Delivery Status Notification.

 Delivery to the following recipients failed.

        cloud_zero1 at

 Content-Type: message/delivery-status

 Reporting-MTA: dns;
 Received-From-MTA: dns;
 Arrival-Date: Wed, 14 Apr 2004 13:14:19 -0700

 Final-Recipient: rfc822;cloud_zero1 at
 Action: failed
 Status: 5.2.3
 Diagnostic-Code: smtp;552 5.2.3 This message is larger than the current system limit or the recipient's mailbox is full. Create a shorter message body or remove attachments and try sending it again.


Granted, it's a DSN for an over-quota user, not a nonexistent user, but
the rejection happens after accept, and the DNS goes to the forged sender.


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