Hmm, which 'From' address is evaluated?

From: Benoit Panizzon <>
Date: Thu, 29 Nov 2012 10:04:04 +0100

Hello Opendkim users

I started using DKIM some time ago. I also operate Spamtraps and a DNS Based
Blacklist, which is feed from these Spamtraps.

Lately I noticed that some emails I bounce to my spamtrap are not processed
anymore, but rejected by sendmail with 'unknown mailer error 9'

I did dig into the problem and it was caused by Opendkim rejecting those
emails with:
    (reason: 550 5.7.0 bad DKIM signature data)

Mainly emails with fake yahoo or paypal in-mail From: header.

Well, when I bounce an email to my spamtrap, the envelope sender is set to my
email address, but the Original in-message From: stays the same, as the
headers should all stay the same for parsing by my spamtrap scripts.

It looks like Opendkim takes the in-message From: instead of the envelope from
to do the checks.
Is this expected behaviour or is this a bug?

If this is expected, is there a work-around for this special case? I bounce
them from 'localhost' and is defined as internal host.

SPAM SPAM SPAM SPAM / Hormel's new miracle meat in a can
Tastes fine, saves time. / If you want something grand, / Ask for SPAM!
  - Hormel's 1937 jingle for SPAM
Hippopotomonstrosesquippedaliophobia sh:
Received on Thu Nov 29 2012 - 09:04:19 PST

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