Can DCC reject mailed-back non-delivery reports?

Gary Mills
Mon Aug 27 15:46:58 UTC 2007

We've had a couple of incidents where people's mailboxes have been
inundated with backscatter because spammers have been forging their
e-mail address as the sender of spam.  I'm ready to reject all mailed-
back non-delivery reports, if sendmail could do that, but I'm wondering
if DCC has a way to do it.  Perhaps DCC could be more selective.

A sendmail log entry looks like this:

    Aug 22 09:20:52 electra sm-mta[19211]: [ID 801593] l7MEKpTH019211: from=<>, size=12709, class=0, nrcpts=1, msgid=<>, proto=ESMTP, daemon=MTA, []

In this instance, the backscatter is from France Telecom.  Their MX is, which suggests it's one of those lovely
anti-spam appliances that's doing the dirty work.

When the message is delivered here, the interesting headers are:

    From: Mail Delivery Subsystem <>
    Message-Id: <>
    MIME-Version: 1.0
    Content-Type: multipart/report; report-type=delivery-status;
    Subject: Returned mail: see transcript for details
    Auto-Submitted: auto-generated (failure)
    X-DCC-UofM-Metrics: electra 1033; Body=1 Fuz1=1 Fuz2=1

Is there anything here that DCC can grab onto?

-Gary Mills-    -Unix Support-    -U of M Academic Computing and Networking-

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