isHtml example

        if (!empty($fromMail) && !empty($fromName)) {
            $mail->setFrom($fromMail, $fromName);
        } elseif (!empty($fromMail)) {
            $mail->setFrom($fromMail);
        }

        $bodyText = $stringCompiler->compileString($mailModel->getContent());
        $mail->setBodyText($bodyText);

        if ($mailModel->isHtml()) {
            $mail->setBodyHtml($stringCompiler->compileString($mailModel->getContentHtml()));
        }

        foreach ($mailModel->getAttachments() as $attachment) {
            if ($attachment->getShopId() !== null
                && ($this->getShop() === null || $attachment->getShopId() !== $this->getShop()->getId())) {
                continue;
            }

            $mediaService = Shopware()->Container()->get(MediaServiceInterface::class);
            if (!$mediaService->has($attachment->getPath())) {