# Get user or create user from recipient's domain
        user = self.user_service.get_user_by_email(
            email=recipient_email.email_address
        )
        if not user:  # User does not exist, create prototype user
            user = EntityUser.create(email=recipient_email.email_address, password='', prototype=True)
            self.user_service.create_user(user=user)