To select a saved template, click on 'Email Templates' and a pop-up screen appears to allow you to select an email template from your library. Select a folder and all templates in that folder will be listed. Select the template you require and click Use Template. The wording of the template will appear in the text box.
You can also save an email you have just constructed as a template by clicking on Save Template on the right hand side of the screen next to the Preview button. Give your template a name and choose a folder from the drop down list. It will be saved to your template library for future use.