From: Garage team <garagehq@deuxfleurs.fr>
Content-Type: multipart/mixed; boundary="parent";
Subject: Welcome to Aerogramme!!

--parent
Content-Type: multipart/mixed; boundary="child";

--child
Content-Type: text/plain; charset="us-ascii"

Hello 1

--child
Content-Type: text/plain; charset="us-ascii"

Hello 2
--child--
--parent
Content-Type: text/plain; charset="us-ascii"

Hello 3
--parent--