Subject: W30 object attached Message-ID: 12345@example.org Date: Fri, 03 Dec 2021 10:00:27 +0000 To: alice@example.org From: bob@example.org Chat-Version: 1.0 Content-Type: multipart/mixed; boundary="==BREAK==" --==BREAK== Content-Type: text/plain; charset=utf-8 w30 with good extension; the mimetype is ignored then. --==BREAK== Content-Type: text/html Content-Disposition: attachment; filename=index.w30 hey! --==BREAK==--