[Mimedefang] Problem with backscatter

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--- On Wed, 3/24/10, Jakub Wasielewski <jakub at wasielewski.info> wrote:
> ...
> The whole session looks like this:
> 
> Mar 20 04:54:16 [mimedefang.pl] o2K3sEnS001039: SPF implemented=no,
> result=neutral, smtp_comment=, header_comment=_
> Mar 20 04:54:17 [mimedefang.pl] o2K3sEnS001039:
> md_check_against_smtp_server for <proboszczd at parafia-sw-stefana.pl> on
> petrus.opoka.org.pl returned 550 5.1.1 <proboszczd at parafia-sw-stefana.pl>:
> Recipient address rejected: User unknown_
> Mar 20 04:54:17 [sm-mta] o2K3sEnS001039: Milter: to=<proboszczd at parafia-sw-stefana.pl>,
> reject=550 5.1.1 <proboszczd at parafia-sw-stefana.pl>:
> Recipient address rejected: User unknown
> Mar 20 04:54:18 [sm-mta] o2K3sEnS001039: from=<kheevwegrjce at alamodome.com>,
> size=446, class=0, nrcpts=2,

Log shows only one recipient processed (and rejected), so how did we get nrcpts=2 ???

> msgid=<000e01cac7e0$ede91e40$00426158 at dusdeffqwta>, proto=ESMTP,
> daemon=MTA, relay=localhost [222.254.116.232] (may be forged)

OK, so DNS info inconsistent.  Some people consider that a valid reason to reject the message.

> Mar 20 04:54:18 [clamd]
> /var/spool/MIMEDefang/mdefang-o2K3sEnS001039/Work/msg-3183-256.txt: OK_
> Mar 20 04:54:18 [clamd]
> /var/spool/MIMEDefang/mdefang-o2K3sEnS001039/Work/INPUTMBOX: OK_
> Mar 20 04:54:18 [mimedefang.pl]
> MDLOG,o2K3sEnS001039,mail_in,,,<kheevwegrjce at alamodome.com>,<proboszcz at parafia-sw-stefana.pl>,The golden nugget has arrived_
> Mar 20 04:54:18 [sm-mta] o2K3sEnS001039: Milter add: header:
> X-Scanned-By: MIMEDefang 2.64 on 212.160.91.130
> Mar 20 04:54:18 [sm-mta] o2K3sEnS001039: to=<proboszczd at parafia-sw-stefana.pl>,
> delay=00:00:01, xdelay=00:00:00, mailer=esmtp, pri=5446, relay=petrus.opoka.org.pl.
> [212.2.120.8], dsn=5.1.1, stat=User unknown
> Mar 20 04:54:18 [sm-mta] o2K3sEnS001039: to=<proboszcz at parafia-sw-stefana.pl>,
> delay=00:00:01, xdelay=00:00:00, mailer=esmtp, pri=5446, relay=petrus.opoka.org.pl.
> [212.2.120.8], dsn=2.0.0, stat=Sent (Ok: queued as D33FE259E5)
> Mar 20 04:54:18 [sm-mta] o2K3sEnS001039: o2K3sInS001048:
> DSN: User unknown
> 
> This is really weird, Milter rejects the recipients, and
> then there is nrcpts=2...

That shouldn't be happening.  Your MTA is screwed.

What precise MTA (and if precompiled, distribution) are you using?

Have you considered your own configuration files?