Content-Type: multipart/alternative; boundary="===============5006593052976639648==" MIME-Version: 1.0 Subject: My subject From: foo@example.org To: bar@example.net --===============5006593052976639648== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit This is HTML --===============5006593052976639648== Content-Type: text/html; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit This is HTML --===============5006593052976639648==--