To: recipient@example.invalid From: sender@example.invalid Subject: HTML quoted-printable body ending on a soft line break Message-ID: Date: Mon, 6 Jul 2026 06:06:06 +0000 MIME-Version: 1.0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

The needle qptrailinghtml sits in the aggregated part.