Mailing template not picking up images
The issue seemed to have been caused by an automatically created .htaccess file in the Resource Image folder. This is being automatically generated but I don't know by what. The contents of the automatically generated file was 

  Order allow,deny
  Deny from all

This prevented the image file from being access. As a quick fix I renamed the file and a new file was there again in less than a minute. I edited the file to allow access and that resolved the issue. 
Though I don't understand where the htaccess file is created from, this can be marked as resolved. Thanks