Pimcore\Document\Newsletter\AddressSourceAdapterInterface::getMailAddressesForBatchSending PHP Method

    public function getMailAddressesForBatchSending();

 protected function doSendMailInBatchMode(Model\Document\Newsletter $document, AddressSourceAdapterInterface $addressAdapter, $sendingId)
 {
     $mail = \Pimcore\Tool\Newsletter::prepareMail($document);
     $sendingParamContainers = $addressAdapter->getMailAddressesForBatchSending();
     $currentCount = 0;
     $totalCount = $addressAdapter->getTotalRecordCount();
     //calculate page size based on total item count - with min page size 3 and max page size 10
     $fifth = $totalCount / 5;
     $pageSize = $fifth > 10 ? 10 : ($fifth < 3 ? 3 : intval($fifth));
     foreach ($sendingParamContainers as $sendingParamContainer) {
         $tmpStore = Model\Tool\TmpStore::get($sendingId);
         if (empty($tmpStore)) {
             Logger::warn("Sending configuration for sending ID {$sendingId} was deleted. Cancelling sending process.");
             exit;
         }
         if ($currentCount % $pageSize == 0) {
             Logger::info("Sending newsletter " . $currentCount . " / " . $totalCount . " [" . $document->getId() . "]");
             $data = $tmpStore->getData();
             $data['progress'] = round($currentCount / $totalCount * 100, 2);
             $tmpStore->setData($data);
             $tmpStore->update();
             \Pimcore::collectGarbage();
         }
         \Pimcore\Tool\Newsletter::sendNewsletterDocumentBasedMail($mail, $sendingParamContainer);
         $currentCount++;
     }
 }