Pimcore\Mail::checkDebugMode PHP Method

    protected function checkDebugMode()
    {
        if (\Pimcore::inDebugMode()) {
            if (empty(self::$debugEmailAddresses)) {
                throw new \Exception('No valid debug email address given in "Settings" -> "System" -> "Email Settings"');
            }
            if ($this->preventDebugInformationAppending != true) {
                //adding the debug information to the html email
                $html = $this->getBodyHtml();
                if ($html instanceof \Zend_Mime_Part) {
                    $rawHtml = $html->getRawContent();
                    $debugInformation = MailHelper::getDebugInformation('html', $this);
                    $debugInformationStyling = MailHelper::getDebugInformationCssStyle();
                    $rawHtml = preg_replace("!(</\\s*body\\s*>)!is", "{$debugInformation}\\1", $rawHtml);
                    $rawHtml = preg_replace("!(<\\s*head\\s*>)!is", "\\1{$debugInformationStyling}", $rawHtml);
                    $this->setBodyHtml($rawHtml);
                }
                $text = $this->getBodyText();
                if ($text instanceof \Zend_Mime_Part) {
                    $rawText = $text->getRawContent();
                    $debugInformation = MailHelper::getDebugInformation('text', $this);
                    $rawText .= $debugInformation;
                    $this->setBodyText($rawText);
                }
                //setting debug subject
                $subject = $this->getSubject();
                $this->clearSubject();
                $this->setSubject('Debug email: ' . $subject);
            }
            $this->clearRecipients();
            $this->addTo(self::$debugEmailAddresses);
        }
    }