The notification e-mail sent from Quickbuild has MIME Content-Type set to multipart/mixed. This format is not well-recognized in all mail clients, for example - you can have problems with inline images in clients like Thunderbird, Apple mail. It would be better to have multipart/alternative - or even have this option configurable.

How to reproduce the problem :

Send this e-mail from quickbuild as a notification to a thunderbird receiver. Include any image named chick.png as an attachment.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<div dir="ltr">
  <div>
    <div>cos tam cos tam<br>
      <div><img src="cid:chick.png"><br>
    </div>?bla bla bla<br><br>
  </div>Pozdr,<br>
</div>A<br></div>