Hello, i Am trying to return an email template when sla status fails as follows but i am not getting any mail after fail.

here is my code 

  for status in self:

            if status.reached_datetime:  # if reached_datetime, SLA is finished: either failed or succeeded

                if status.reached_datetime < status.deadline:

                    status.status = 'reached'

                else:

                    status.status = 'failed'

            else:  # if not finished, deadline should be compared to now()

                if status.deadline > fields.Datetime.now():

                    status.status = 'ongoing'

                else:

                    status.status = 'failed'

                    return self.env.ref('helpdesk.solved_ticket_request_email_template')