Wo lassen manche Postmaster denken?

Da läßt jemand sei­nen Mail­ser­ver für Phis­hing offen, jemand anders möch­te einen mei­ner User abphishen:_ Mail von helpdesk@example.com an user@example.com. (Ich bin example.com)

293bf839-d15c-4677-a6b0-d568ea98c062_
Content-Type: text/plain

Hello, this is the mail server on rdns0.asiltransp.cyou.

I am sending you this message to inform you on the delivery status of a
message you previously sent. Immediately below you will find a list of
the affected recipients; also attached is a Delivery Status Notification
(DSN) report in standard format, as well as the headers of the original
message.

<user@example.com> delivery failed; will not continue trying

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Content-Type: message/delivery-status

Reporting-MTA: dns;rdns0.asiltransp.cyou
X-PowerMTA-VirtualMTA: pmta-vmta0
Received-From-MTA: dns;example.com (185.219.168.9)
Arrival-Date: Tue, 18 Aug 2020 00:55:03 -0500

Final-Recipient: rfc822;user@example.com
Action: failed
Status: 5.7.1 (delivery not authorized)
Remote-MTA: dns;mx1.example.com (x.x.x.x)
Diagnostic-Code: smtp;550 5.7.1 rejected by DMARC policy for example.com
X-PowerMTA-BounceCategory: policy-related

--_293bf839-d15c-4677-a6b0-d568ea98c062_
Content-Type: text/rfc822-headers

From: example.com cloudmail Support <helpdesk@example.com>
To: user@example.com
Subject: [BULK] Important: user@example.com You have Pending incoming emails.
Date: 17 Aug 2020 22:55:00 -0700
Message-ID: <20200817225500.35CB4A079D00BB4C@example.com>
MIME-Version: 1.0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

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Aber wel­che Kom­pe­tenz will man schon erwar­ten von jeman­dem, der eine cyou-Domain betreibt…