MailTemplateService.php

		$mail->setSendingTime($sendingTime);
		$mail->setLastSendingTime($lastSendingTime);
		$mail->setReplyTo($this->replyToAddress);
		foreach ($this->markers as $marker) {
			if ($marker instanceof FileReference) {
				$mail->addAttachment($marker);
			}
		}

		$mailRepository = $this->objectManager->get(MailRepository::class);
		$mailRepository->add($mail);
		$this->persistenceManager->persistAll();
		return $mail;
	}

	/**
	 * Send a Mail from the queue, identified by its id
	 *
	 * @param int $uid
	 * @return bool|NULL
	 * @throws \TYPO3\CMS\Extbase\Persistence\Exception\IllegalObjectTypeException
	 * @throws \TYPO3\CMS\Extbase\Persistence\Exception\UnknownObjectException
	 * @throws \Exception
	 */
	public function sendMailFromQueue($uid): bool {
		$mailRepository = $this->objectManager->get(MailRepository::class);
		/** @var Mail $mailToSend */
		$mailToSend = $mailRepository->findOneByUid($uid);
		if (!$mailToSend || $mailToSend->getBlacklisted()) {
			return FALSE;
		}

		$this->mailMessage->setBody($mailToSend->getMailBody(), 'text/html');
		$plaintextService = GeneralUtility::makeInstance(PlaintextService::class);
		$plaintextBody = $plaintextService->makePlain($mailToSend->getMailBody());
		$this->mailMessage->addPart($plaintextBody, 'text/plain');
		$toAddresses = \trim($mailToSend->getToAddress());
		$addressesArray = GeneralUtility::trimExplode(',', $toAddresses, TRUE);
		if (\count($addressesArray) > 1) {
			$toAddresses = $addressesArray;
		}
		$this->mailMessage->setTo($toAddresses);
		$this->mailMessage->setFrom($mailToSend->getFromAddress(), $mailToSend->getFromName());
		$this->mailMessage->setSubject($mailToSend->getMailSubject());

		if ($mailToSend->getBccAddresses()) {
			$this->mailMessage->setBcc(GeneralUtility::trimExplode(',', $mailToSend->getBccAddresses()));
		}

		if ($mailToSend->getCcAddresses()) {
			$this->mailMessage->setCc(GeneralUtility::trimExplode(',', $mailToSend->getCcAddresses()));
		}

		if ($mailToSend->getReplyTo()) {
			$this->mailMessage->setReplyTo($mailToSend->getReplyTo());
		}
		$attachments = $mailToSend->getAttachments();
		if ($attachments->count() > 0) {
			foreach ($attachments as $attachment) {
				/**
				 * @var FileReference $attachment
				 */
				$file = $attachment->getOriginalResource()->getOriginalFile();
				$this->mailMessage->attach(
					\Swift_Attachment::newInstance($file->getContents(), $file->getName(), $file->getMimeType())
				);
			}
		}
		$dateTime = new DateTime();
		if ((int) $mailToSend->getSendingTime() === 0) {
			$mailToSend->setSendingTime($dateTime->getTimestamp());
		}
		$mailToSend->setLastSendingTime($dateTime->getTimestamp());
		$success = $this->mailMessage->send();
		if ($success) {
			$mailRepository->update($mailToSend);
			$this->persistenceManager->persistAll();
		} else {
			$this->mailMessage->getFailedRecipients();
		}
		return $success;
	}

	/**
	 * @return string
	 */
	public function getOverwrittenBcc(): string {
		return $this->overwrittenBcc;
	}

	/**
	 * @param string $overwrittenBcc
	 */
	public function setOverwrittenBcc(string $overwrittenBcc): void {
		$this->overwrittenBcc = $overwrittenBcc;
	}

	/**
	 * @return string
	 */
	public function getOverwrittenCc(): string {
		return $this->overwrittenCc;
	}

	/**
	 * @param string $overwrittenCc
	 */
	public function setOverwrittenCc(string $overwrittenCc): void {
		$this->overwrittenCc = $overwrittenCc;
	}

	/**
	 * @return string
	 */
	public function getOverwrittenFromName(): string {
		return $this->overwrittenFromName;
	}

	/**
	 * @param string $overwrittenFromName
	 */
	public function setOverwrittenFromName(string $overwrittenFromName): void {
		$this->overwrittenFromName = $overwrittenFromName;
	}

	/**
	 * @return string
	 */
	public function getOverwrittenFromMail(): string {
		return $this->overwrittenFromMail;
	}

	/**
	 * @param string $overwrittenFromMail
	 */
	public function setOverwrittenFromMail(string $overwrittenFromMail): void {
		$this->overwrittenFromMail = $overwrittenFromMail;
	}

	/**
	 * @return string
	 */
	public function getOverwrittenReplyTo(): string {
		return $this->overwrittenReplyTo;
	}

	/**
	 * @param string $overwrittenReplyTo
	 */
	public function setOverwrittenReplyTo(string $overwrittenReplyTo): void {
		$this->overwrittenReplyTo = $overwrittenReplyTo;
	}

	/**
	 * @return string
	 */
	public function getOverwrittenToAddresses(): string {
		return $this->overwrittenToAddresses;
	}

	/**
	 * @param string $overwrittenToAddresses
	 */
	public function setOverwrittenToAddresses(string $overwrittenToAddresses): void {
		$this->overwrittenToAddresses = $overwrittenToAddresses;
	}

	/**
	 * Sets the fromMail property of the mailTemplateService.
	 * Checks validity and uses all available fallbacks
	 *
	 * @param string $fromMail
	 * @return string
	 */
	private function getValidFromMail($fromMail): string {
		$fromMail = \trim($fromMail);
		if (!\filter_var($fromMail, FILTER_VALIDATE_EMAIL)) {
			$fromMail = $this->fromAddress;
		}
		if (!\filter_var($fromMail, FILTER_VALIDATE_EMAIL)) {
			$fromMail = $GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress'];
			if (!\filter_var($GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress'], FILTER_VALIDATE_EMAIL)) {
				$fromMail = 'noreply@example.com';
			}
		}

		return $fromMail;
	}

	/**
	 * Get a single variable containing a list of all markers
	 *
	 * @param array $markers
	 * @return string
	 */
	private function getAllMarker(array $markers): string {
		$allMarker = '';

		foreach ($markers as $key => $value) {
			if (\array_key_exists($key, $this->markerLabels) && $this->markerLabels[$key] !== NULL) {
				$key = $this->markerLabels[$key];
			}

			if (\is_string($value)) {
				$allMarker .= $key . ': ' . $value . PHP_EOL;
			} elseif (\is_array($value)) {
				foreach ($value as $innerKey => $innerValue) {
					$allMarker .= $key . '.' . $innerKey . ': ' . $innerValue . PHP_EOL;
				}
			} elseif (\is_bool($value)) {
				$valueAsString = $value ? 'true' : 'false';
				$allMarker .= $key . ': ' . $valueAsString . PHP_EOL;
			} elseif (\is_object($value)) {
				if (\method_exists($value, '__toString')) {
					$allMarker .= $key . ': ' . $value->__toString() . PHP_EOL;
				}
			}
		}

		return $allMarker;
	}
}