Import_mbox.sh not working with e-mails from Samsung phone sent via a listserv server

Here is a contrived e-mail I’ve made that I think demonstrates the problem. If you look at the HTML part it has a reply to an earlier message. The importer doesn’t seem to be able to see where the original message started.

From someone@gmail
Delivered-To: someone@gmail
Importance: Normal
MIME-Version: 1.0
Message-ID: <E1mt6gg-00H2OV-6N@relay01.mail.eu.clara.net>
Date: Fri, 3 Dec 2021 11:25:05 +0000
From: someone <someone@somewhere.net>
Subject: Re: Example e-mail
To: <LIST@LISTSERV>
In-Reply-To: <007301d7e834$c268a3e0$4739eba0$@sslmc.co.uk>
Precedence: list
Content-Type: multipart/alternative;
	boundary="--_com.samsung.android.email_7076959834053910"

----_com.samsung.android.email_7076959834053910
Content-Transfer-Encoding: base64
Content-Type: text/plain; charset=UTF-8

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----_com.samsung.android.email_7076959834053910
Content-Transfer-Encoding: base64
Content-Type: text/html; charset=UTF-8

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----_com.samsung.android.email_7076959834053910--