Content-Type: multipart/mixed; boundary=longrandomstring
From: Sender <sender@pm.me>
To: Receiver <receiver@pm.me>


This is a multi-part message in MIME format.
--longrandomstring
Content-Transfer-Encoding: base64
Content-Type: text/html

PGh0bWw+PGJvZHk+VGhpcyBpcyBib2R5IG9mIDxiPkhUTUwgbWFpbDwvYj4gd2l0aCBhdHRhY2htZW50PC9ib2R5PjwvaHRtbD4=
--longrandomstring
Content-Disposition: attachment
Content-Transfer-Encoding: base64

YXR0YWNobWVudA==
--longrandomstring--
.