the = characters in your message are a special coding line 
formatting which is not handled well by the lute mail robot.
You will notice that Rob's part of the message has far
fewer of these = signs.  That is because he uses the
return key to make each line shorter than 80 characters.
If you use the return key at the end of each line, like
one would on a typewriter, you will avoid this problem.
<p>
Now for the technical part..
<p>
 You are sending mail as text/html  and quoted-printable.
The = sign is actually part of the quoted printable specification,
and the lute mail robot does not handle it.  If you were to
set your "Content-Transfer-Encoding" to 7bit or plain or
maybe ascii it might work better.  I really can't tell
you exactly how to do this because every mailer is a little
different and I have no idea what mailer you use, and
probably have never seen it either!)
<p>
 the = sign is used to indicate that a long line (with no
carriage return) is being broken into 80 character lengths to go
through the mail, as some mail systems actually chop off
the end of  every line after 80 characters.
<p>
 If all the mail browsers in the world used exactly the
same format it would be much easier for me to write a robot
to handle them all, but it isn't that way.