Create a new email with the subject and content you would like the template to contain.
Go to File (on your email message, not your mailbox), Save As. Select “Outlook Template” from the FileType dropdown and save it to your desktop.
Drag and drop the email template from your desktop into a designated folder within your Outlook.
Now it’s ready for you to use. Double click the template and a new email will be created. When you send the email off, the original template will remain in your template folder.