Missing html head and body tags? [#2280973]

I'm not exactly sure where to post this issue as it sort of involves Simplenews, MimeMail and HTMLMail.

I use the Simplenews module in combination with the Mime Mail module in order to send HTML newsletters. Everything worked fine until recently when i started to add image links to the newsletters. When i open the emails in Apple Mail the pointer doesn't show when hovering over the image link, but the links work when i click them. Troubleshooting this issue i have noticed that my emails don't contain doc type declarations, <html>, <head> and <body> tags.

I tried adding these tags to the following files with no success:

simplenews-newsletter-body.tpl.php
htmlmail--simplenews.tpl.php

I clear the cache, and the template files are recognised and are showing any other content that i added to them. But not the above mentioned tags.

Does Simpleness, Mime Mail or HTMLmail strip out this part of the html document? I know the tags are not required, but it seems odd that i can't even add them if i wanted to. And by adding them i'm hoping to solve my issue with the missing pointers....