simplenews-newsletter-body.tpl.php won't be overridden My newsletter is almost ready, where it not that the node title ends up in the sent testmail as well. So I figured if I would just override the simplenews-newsletter-body.tpl.php
I followed the guidelines from this page.

In my simplenews configuration I just checked just the generic content type that simplenews generated. In that same configuration page, I chose 'newsletter' as the taxonomy term attached to it. This makes the filename simplenews-newsletter-body--newsletter.tpl.php

The idea to just delete the following line from the copied file: 
&lt;h2&gt;&lt;?php print $title ?&gt;&lt;/h2&gt;

The tutorial I mentioned says to paste in into the custom theme folder directly. I was assuming not in the templates folder. I tried both though while flushing cashes at least twice after each try. Still getting the darn title in my test mail. 

UPDATE: I discovered that the filename needs to be the term ID of the simplenews newsletter, being a number. I looked up the tid and changed the tpl filename accordingly - in my case making it simplenews-newsletter-body--110.tpl.php. Of course the needed flushing of cashes. Didn't help either.
The file may need to go in the admin theme folder, if you're using admin theme/sections, and not in the regular theme folder. Worth a shot.