From: Alice <alice@example.org>
Subject: Both parts
Date: Sat, 01 Aug 2026 10:00:00 +0000
Message-ID: <alt-1@example.org>
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="BOUND"

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Content-Type: text/plain; charset=utf-8

plain version
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Content-Type: text/html; charset=utf-8

<html><body><p>html version</p></body></html>
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