private function isCampaignValid($campaign)
    {
        if (! $campaign->getCampaignId()) {
            $campaign->setMessage('Missing campaign id: ' . $campaign->getCampaignId())
                ->setSendStatus(\Dotdigitalgroup\Email\Model\Campaign::FAILED);
            $this->campaignResourceModel->saveItem($campaign);
            return false;
        } elseif (! $campaign->getEmail()) {
            $campaign->setMessage('Missing email')
                ->setSendStatus(\Dotdigitalgroup\Email\Model\Campaign::FAILED);
            $this->campaignResourceModel->saveItem($campaign);
            return false;
        }
        return true;
    }