From: Ye Olde Sender Subject: Nested message 1 To: my list Message-ID: Date: Wed, 8 Jan 2020 12:27:55 +0100 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="________boundary-level1" Content-Language: en-US This message is a normal multipart/mixed message without nested multiparts. --________boundary-level1 Content-Type: multipart/alternative; boundary="________boundary-level2" --________boundary-level2 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit A Simple text part --________boundary-level2 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit A simple HTML part. --________boundary-level2-- --________boundary-level1 Content-Type: application/pdf; name="attachment.pdf" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="attachment.pdf" JVBERi0xLjQNJeLjz9MNCjUgMCBvYmoNPDwvTGluZWFyaXplZCAxL0wgMTIzNzgxNi9PIDcv --________boundary-level1--