Content-Type: multipart/alternative;
 boundary="------------{boundary}"
MIME-Version: 1.0
X-Mailer: PHP {phpversion}
To: {mymailto}
From: {von}
Subject: {mysubject

This is a multi-part message in MIME format.
--------------{boundary}
Content-Type: text/plain; charset={utfencoding}; format=flowed
Content-Transfer-Encoding: 7bit

beides html und text

--------------{boundary}
Content-Type: text/html; charset={utfencoding}
Content-Transfer-Encoding: 7bit

{mycontent}

--------------{boundary}
