The ISN has a great place for you to browse and download new email templates and containers into your ISN. Go to Email -- Get Templates & Containers and you can browse or download a list of new and old email templates and containers. Simply click the tabs at the top of the list to switch between templates and containers.
To add the Template or Container to your ISN, simply click on the green 'Copy to this ISN' button.
If you want to preview the container or template just click the blue 'View' button.
ISN will tell you if you already have it in your ISN and allow you to copy it over again.
Once copied your templates and containers can be found under Email -- My Email Templates and Email -- My Email Containers respectively.