This is something new in my experience - the delivery of an email without a sender's email address. In fact four of them all from the same sources at almost the same time.
Surely something that fundamentally flawed should never pass authentication? (But I'm only the dum customer so wot would I kno?)

Here is an extract of the header information:
Received: from 10.220.161.203
by atlas308.free.mail.ne1.yahoo.com pod-id NONE with HTTPS; Tue, 6 Jun 2023 15:55:41 +0000
Return-Path: return@kriegstagebuch.shop
X-Originating-Ip: [69.48.142.86]
Received-SPF: pass (domain of kriegstagebuch.shop designates 69.48.142.86 as permitted sender)
Authentication-Results: atlas308.free.mail.ne1.yahoo.com;
dkim=unknown;
spf=pass smtp.mailfrom=kriegstagebuch.shop;
dmarc=unknown reason=from header is empty;
X-Apparently-To: XXXXXXXXXXXXXXXX@yahoo.com; Tue, 6 Jun 2023 15:55:41 +0000
X-YMailAVSC:
....
Received: from 69.48.142.86 (EHLO kriegstagebuch.shop)
by 10.220.161.203 with SMTP;
Tue, 06 Jun 2023 15:55:41 +0000
Subject: PH: If you think this could never happen to you, think again.
From: Martin D. Weiss, PhD
Reply-To: LOTHEBROK NENNER <reply_to@kriegstagebuch.shop>
To: XXXXXXXXXXXXXXXX@yahoo.com
Date: Tue, 06 Jun 2023 17:55:37 +0200
Message-ID: 1317150aqUbu5tzdc30.8ebff2511e.202cEwmqZu2.i1caUv8Q.6302682@kriegstagebuch.shop
X-Mailer: SHADOWFOX Mailer - hAQQYzJki-946 - CID5320d9jZ2ULaMri
X-Campaign: SHADOWFOX1317150a9d5b9jZ2ULaMri.i1caUv8Q
X-hAQQYzJki-946-Campaign: SHADOWFOX1317150a9d5b9jZ2ULaMri.i1caUv8Q
X-campaignid: SHADOWFOX13179jZ2ULaMric30.5320d9b3d7
X-Report-Abuse: Please report abuse for this campaign here: https://kriegstagebuch.shop/contact/abuse/?u=a6PMzknHoTXs39FE
X-MC-User: 1317150a9d5b4i1caUv8Q
Feedback-ID: JJXEPqrxso:JJXEPqrxso.JJXEPqrxso:us20:mc
List-ID: JJXEPqrxsomc list <77169320i1caUv8Q30.290295.kriegstagebuch.shop>
List-hAQQYzJki-946-ID: XXXXXXXXXXXXXXXX@yahoo.com
List-Unsubscribe: leave-ZrctoJgWfdKX@kriegstagebuch.shop List-Unsubscribe-Post: List-Unsubscribe=One-Click
Content-Type: text/HTmL;
MIME-Version: 1.0
Content-Length: 1731