Mail::send() 

public function send ( $paramOverrides = [] ) {
	\nn\t3::autoload();
	// Defaults mergen mit Parametern
	$params = [
		'emogrify'	=> true,
		'absPrefix'	=> true,
	];
	ArrayUtility::mergeRecursiveWithOverrule( $params, $paramOverrides);
	$mail = GeneralUtility::makeInstance(MailMessage::class);
	$html = $params['html'] ?? '';
	$pathSite = \nn\t3::Environment()->getPathSite();
	$recipients = \nn\t3::Arrays($params['toEmail'] ?? '')->trimExplode();
	$fromEmail = array_shift(\nn\t3::Arrays($params['fromEmail'] ?? '')->trimExplode());
	if ($replyToEmail = $params['replyToEmail'] ?? false) {
		$mail->replyTo( new \Symfony\Component\Mime\Address($replyToEmail, $params['replyToName'] ?? '') );
	}
	if ($ccToEmail = $params['ccToEmail'] ?? false) {
		$ccToEmail = \nn\t3::Arrays($ccToEmail)->trimExplode();
		$mail->setCc( $ccToEmail );
	}
	if ($bccToEmail = $params['bccToEmail'] ?? false) {
		$bccToEmail = \nn\t3::Arrays($bccToEmail)->trimExplode();
		$mail->setBcc( $bccToEmail );
	}
	$mail->from( new \Symfony\Component\Mime\Address($fromEmail, $params['fromName'] ?? '') );
	$mail->to(...$recipients);
	$mail->subject($params['subject'] ?? '');
	// Inline-Media im HTML-Code finden (<img data-embed="1" src="..." />)
	$dom = new \DOMDocument();
	@$dom->loadHTML($html);
	// XPATH Cheat-Sheet: https://devhints.io/xpath
	$xpath = new \DOMXPath($dom);
	$nodes = $xpath->query('//*[@data-embed]');
	$attachedFiles = [];
	foreach ($nodes as $node) {
		if ($img = $node->getAttribute('src')) {
			$node->removeAttribute('data-embed');
			$cid = 'img-' . md5($pathSite . $img);
			$node->setAttribute('src', 'cid:'.$cid);
			$mail->embedFromPath( $pathSite . $img, $cid );
		}
		if ($file = $node->getAttribute('href')) {
			if (!isset($attachedFiles[$pathSite . $file])) {
				$absPath = \nn\t3::File()->absPath( $file );
				$mail->attachFromPath( $absPath );
				$attachedFiles[$absPath] = true;
			}
		}
	}
	// Zusätzlich Anhänge?
	$attachments = \nn\t3::Arrays($params['attachments'] ?? '')->trimExplode();
	foreach ($attachments as $path) {
		if (!isset($attachedFiles[$pathSite . $path])) {
			$absPath = \nn\t3::File()->absPath( $path );
			$mail->attachFromPath( $absPath );
			$attachedFiles[ $absPath ] = true;
		}
	}
	$html = $dom->saveHTML();
	// Relative Pfade im Quelltext mit absoluten Pfaden ersetzen
	if ($params['absPrefix'] ?? false) {
		$html = \nn\t3::Dom()->absPrefix( $html );
	}
	// CSS in Inline-Styles umwandeln
	if ($params['emogrify'] ?? false) {
		$html = CssInliner::fromHtml($html)->inlineCss()->render();
	}
	$plaintext = $params['plaintext'] ?? strip_tags($html);
	if ($html) {
		$mail->html($html);
		$mail->text($plaintext);
	} else {
		$mail->text($plaintext);
	}
	$returnPath = $params['returnPath_email'] ?? \TYPO3\CMS\Core\Utility\MailUtility::getSystemFromAddress();
	if (strpos($returnPath, 'no-reply') === false) {
		$mail->setReturnPath( $returnPath );
	}
	// zsätzliche Header?
	if ($headers = $params['headers'] ?? false) {
		$mailHeaders = $mail->getHeaders();
		foreach ($headers as $k=>$v) {
			$mailHeaders->addTextHeader($k, $v);
		}
	}
	$sent = $mail->send();
	if (!$sent) {
/*
		\nn\t3::Log()->error('nnhelpers', 'Mail not sent', $recipients);
		$fp = fopen('mail_error.log', 'a');
		$to = join(',', $recipients);
		fputs($fp, date('d.m.Y H:i:s')." {$to}\n\n\n");
		fclose($fp);
		$helpMail = $this->params['errorMail_email'];
		$mail->setReturnPath( $helpMail );
		$mail->setTo( $helpMail );
		$mail->setSubject('Mailversand: FEHLER!');
		$mail->send();
//*/
	}
	return $sent;
}