[Exim] Weird bit-flipping in sender address..

Top Page
Delete this message
Reply to this message
Author: Dave C.
Date:  
To: exim-users
Subject: [Exim] Weird bit-flipping in sender address..
I'm not sure if this is an exim problem, an os/library problem, a
hardware problem, or some sort of new and deranged Outlook Express
virus/worm.

RedHat 5.x (Yes I know its ancient),

exim was 3.15, just upgraded to 3.33 to try and solve this problem - but
it still occurs..

The server we provide for 'outgoing' SMTP relay for our customers is
configured to verify sender address when its in one of our local
domains.

Lately I have been seeing quite a few instances of the second character
of the senders address, getting bit-flipped, in the _envelope_ only.
This of course causes exim to reject the message assuming the
bit-flipped address is not valid. Its always the second character, and
it always is one higher than the correct character (which is still
visible in the From: header email addres)

I'm not sure if the client MUA is bitflipping the address, or if exim
(or some underlying system component on the server) is..

I'm wondering if anyone else with a similar configuration is seeing
anything like this - if so, then I will suspect a MUA worm or virus and
will quit tearing my hair out as to why my server has suddenly gone
mad..

An example of what I am seeing in the logs:

<qwerty@???> is a valid address.

------------------------------------------------------------------------------
2001-08-22 10:20:00 15ZYr7-0003j4-00 rejected from dialup-IP-xx-94.domain.com (domain.com) [xx.xx.xx.94]: unknown
 local part in sender <qxerty@???>
Recipients: someone@???
P Received: from dialup-IP-xx-94.domain.com ([xx.xx.xx.94] helo=domain.com)
        by smtp.domain.com with smtp (Exim 3.33 #1)
        id 15ZYr6-0003j4-01; Wed, 22 Aug 2001 10:19:41 -0400
F FROM: Qwerty <qwerty@???>
  SUBJECT: something
  X-MSMail-Priority: Normal
  X-Priority: 3
  X-Mailer: Microsoft Outlook Express 5.00.2919.6600
  MIME-Version: 1.0
  Content-Type: multipart/mixed;
        boundary="----=_NextPart_000_00ED_01AB7EE4.848EE430"
  Content-Transfer-Encoding: 7bit
I Message-Id: <E15ZYr7-0003j4-00@???>
B Bcc:
  Date: Wed, 22 Aug 2001 10:19:41 -0400
------------------------------------------------------------------------------