SORBS a PITA on spam backscatter ...

[Randal, Phil]

The "Scam-backscatter" milter might do what you want.

  http://www.elandsys.com/scam/scam-backscatter/

You need to configure exchange 2003 (or later) to reject invalid
recipients during the SMTP phase for this to work:

 
https://support.interjuncture.com/index.php?_m=knowledgebase&_a=viewarti
cle&kbarticleid=25

Cheers,

Phil
--
Phil Randal
Network Engineer
Herefordshire Council
Hereford, UK  

> -----Original Message-----
> From: mailscanner-bounces at lists.mailscanner.info 
> [mailto:mailscanner-bounces at lists.mailscanner.info] On Behalf 
> Of Garry Glendown
> Sent: 13 June 2007 19:28
> To: MailScanner discussion
> Subject: OT: SORBS a PITA on spam backscatter ...
> 
> Sorry, this is most likely somewhat off topic, but maybe I could get
> some suggestions ...
> 
> One of our customers was hit by a presumably larger amount of spam
> mails, addressed to mail addresses collected somehow, but 
> with errors in
> the addresses (first part of the mail address duplicated, like
> "johnjohn at do.main" instead of "john at do.main"). They are operating a
> multi-level mail service, with MS on our side, delivering to an SMTP
> proxy, then over through a virus scanner, and finally to the 
> actual mail
> server (M$ Exchange). Mails are accepted, even by the Exchange server,
> which in turn generates a non-delivery receipt for wrong addresses.
> 
> For outgoing mail, our central mail server is the smarthost. Which in
> turn got listed on SORBS for delivering spam backscatter ... great. As
> far as I see it, delivering the mails, which in themselves 
> are generated
> in compliance with RFCs, is fully legitimate.
> 
> What should we do? We get complaints due to the fact that 
> certain mails
> sent from other customers are being blocked on recipient 
> mailservers due
> to our server being SORBS-listed ...
> 
> I personally do not see any way of identifying whether such a receipt
> (if I'm able to even decide that it is a non-delivery receipt) is for
> legitimate mails that couldn't be delivered, or for spam.
> 
> Any suggestions?
> 
> tnx, -garry
> 
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> Orwell war ein Optimist
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