With HTML mailings, CiviMail is trying to replace stylesheet reference urls. For example,
When I put the URL in my HTML code as this:
<LINK REL=StyleSheet HREF="http://mysite.org/sites/all/themes/zen/cctv/layout.css" TYPE="text/css" MEDIA=screen>
it turns it into this when the final email comes out:
<LINK REL=StyleSheet href='http://mysite.org/sites/all/modules/civicrm/extern/url.php?u=188&qid=148' TYPE="text/css" MEDIA=screen>
When running this url as a test: http://mysite.org/sites/all/modules/civicrm/extern/url.php?u=188&qid=148
I do not get the stylsheet back; I get my drupal page not found and the URL turns into this:
Absolute urls work fine with other tags such as img src. It should allow absolute urls for stylesheet refs.