mau.py

        try:
            is_auth_blocking = False
            if self._config.mau_limit_alerting:
                try:
                    # Normally should always pass in user_id to check_auth_blocking
                    # if you have it, but in this case are checking what would happen
                    # to other users if they were to arrive.
                    yield self._auth.check_auth_blocking()
                except ResourceLimitError as e:
                    is_auth_blocking = True
                    event_body = e.msg
                    event_limit_type = e.limit_type

            if currently_blocked and not is_auth_blocking:
                # Room is notifying of a block, when it ought not to be.
                yield self._remove_limit_block_notification(user_id, ref_events)
            elif not currently_blocked and is_auth_blocking:
                # Room is not notifying of a block, when it ought to be.
                yield self._apply_limit_block_notification(
                    user_id, event_body, event_limit_type
                )
        except SynapseError as e:
            logger.error("Error sending resource limits server notice: %s", e)