Messages passing through Mailscanner lose X-Mailer headers, and turn up as SPAM, but no Mailscanner no problem

John Van Ostrand john at
Mon Nov 13 22:51:51 GMT 2006

On Mon, 2006-11-13 at 16:42 -0500, Leah Cunningham wrote:
> I have a strange problem.  I have a client whose internal user is able to 
> successfully send messages to me from their old Q-Mail server without a 
> problem. If the same user, with the same mail client, computer, etc, sends a 
> message through a newer mail server that I have set up for them that runs 
> MailScanner (with Postfix), the message is detected by my own mail server 
> (and many others) as Spam, and has different headers.  It seems part of the 
> reason is that Spamassassin thinks it is a bogus Outlook, maybe because the 
> X-Mailer header is not there.  
> The major difference I notice is that in the one that went through 
> MailScanner, we are missing these two headers that are in the one that went 
> through their old mail server, and I want to know why:
> X-Mailer: Microsoft Outlook, Build 10.0.2627
> Importance: Normal
> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180

This may not be much help, but you have received headers missing too.
Based on the Spam report in the second message I think you've identified
the missing Outlook headers as being the key. Find out whether postfix
or Mailscanner is removing them and you should be fine.

I would try a tcpdump on the client's postfix server to see what is
being delivered to postfix. Do a similar one on the outgoing email to at
least confirm that it's the client server.

I use sendmail, where a split queue is used. One may be able to examine
the queue files in each queue if you can stop the processes at the right

Good luck.

John Van Ostrand                       Net Direct Inc.
CTO, co-CEO                   564 Weber St. N. Unit 12
                                  Waterloo, ON N2L 5C6
john at                     ph: 518-883-1172 x5102
Linux Solutions / IBM Hardware        fx: 519-883-8533

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