Comment 2 for bug 1437866

settings.EMAIL_CONFIRMATION_FROM is supposed to contain the general From-Address for email confirmations. self.email in this context however contains the new address someone wants to add to a Mailman user record -- which means the confirmation email would come from the same address it has been sent from.

I think a better fallback for settings.EMAIL_CONFIRMATION_FROM could be settings.DEFAULT_FROM_EMAIL which is suggested as a general Email-`from`-default in the Django docs. If both don't exist it's probably best to raise Django's `ImproperlyConfigured` exception. This will still raise a 500 if settings.DEBUG == False, but the traceback sent to the Admins will be much more meaningful and will alert them to check the configuration rather than looking for a bug in the code.