Synnefo

it best fits your needs  using django’s TEMPLATE_DIRS setting.    

https://docs.djangoproject.com/en/1.2/ref/settings/#template-dirs.                           

In order to overwrite one or more email-templates you need to create a new one 

directory and  provide its path to the TEMPLATE_DIRS. Inside this directory, you

must place your <email-file>.txt files respecting the following structure:

  *<emails-dir>*/

      *im*/

          | activation_email.txt

          | email.txt

          | invitation.txt

          | switch_accounts_email.txt

          | welcome_email.txt

          *projects*/

              | project_approval_notification.txt

              | project_denial_notification.txt    

              | project_membership_change_notification.txt

              | project_membership_enroll_notification.txt

              | project_membership_leave_request_notification.txt

              | project_membership_request_notification.txt

              | project_suspension_notification.txt

              | project_termination_notification.txt

      *registration*/

          | email_change_email.txt

          | password_email.txt

Feel free to omit any of the above files you do not wish to overwrite.