diff --git a/Classes/Configuration.php b/Classes/Configuration.php
new file mode 100644
index 0000000..e62c795
--- /dev/null
+++ b/Classes/Configuration.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace StudioMitte\SentMails;
+
+use TYPO3\CMS\Core\Configuration\ExtensionConfiguration;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+class Configuration
+{
+
+    /** @var string[] */
+    public array $rejectBySearchTerms = [];
+
+    public int $mailInformationMaxTime = 60;
+
+    public string $mailAPIUsername = '';
+    public string $mailAPIPassword = '';
+
+    public function __construct()
+    {
+        try {
+            $settings = GeneralUtility::makeInstance(ExtensionConfiguration::class)->get('sent_mails');
+
+            $this->rejectBySearchTerms = GeneralUtility::trimExplode('|', $settings['rejectBySearchTerms'] ?? '', true);
+            $this->mailAPIUsername = $settings['mailAPIUsername'] ?? '';
+            $this->mailAPIPassword = $settings['mailAPIPassword'] ?? '';
+        } catch (\Exception $e) {
+            // do nothing
+        }
+    }
+
+}
diff --git a/Classes/EventListener/BeforeMailSentEventListener.php b/Classes/EventListener/BeforeMailSentEventListener.php
index cad6884..16398f6 100644
--- a/Classes/EventListener/BeforeMailSentEventListener.php
+++ b/Classes/EventListener/BeforeMailSentEventListener.php
@@ -12,7 +12,6 @@
 use TYPO3\CMS\Core\Utility\ArrayUtility;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Core\Utility\StringUtility;
-use TYPO3\CMS\Extbase\Utility\DebuggerUtility;
 
 class BeforeMailSentEventListener
 {
@@ -36,10 +35,8 @@ public function __invoke(BeforeMailerSentMessageEvent $event): void
 
         $sentMessage->getHeaders()->addTextHeader('X-SentMail_Custom', $customId);
 
-//        $originalMessage = $sentMessage->getOriginalMessage();
         $isReply = get_class($originalMessage) === RawMessage::class;
-//        DebuggerUtility::var_dump($isReply, '$isReply');
-//
+
         $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('tx_sentmail_mail');
         $connection->insert('tx_sentmail_mail', [
             'crdate' => time(),
diff --git a/Classes/EventListener/MailMessageListener.php b/Classes/EventListener/MailMessageListener.php
new file mode 100644
index 0000000..9e21e2a
--- /dev/null
+++ b/Classes/EventListener/MailMessageListener.php
@@ -0,0 +1,30 @@
+<?php
+declare(strict_types=1);
+
+namespace StudioMitte\SentMails\EventListener;
+
+
+use StudioMitte\SentMails\Configuration;
+use Symfony\Component\Mailer\Event\MessageEvent;
+
+class MailMessageListener
+{
+
+    public function __construct(
+        protected Configuration $configuration)
+    {
+    }
+
+    public function __invoke(MessageEvent $event): void
+    {
+        $message = $event->getMessage();
+
+        $messageAsString = $message->toString();
+        foreach ($this->configuration->rejectBySearchTerms as $searchTerm) {
+            if (preg_match(sprintf('/%s/i', $searchTerm), $messageAsString)) {
+                $event->reject();
+                return;
+            }
+        }
+    }
+}
diff --git a/Classes/Middleware/MailInformation.php b/Classes/Middleware/MailInformation.php
new file mode 100644
index 0000000..2573435
--- /dev/null
+++ b/Classes/Middleware/MailInformation.php
@@ -0,0 +1,77 @@
+<?php
+declare(strict_types=1);
+
+namespace StudioMitte\SentMails\Middleware;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use StudioMitte\SentMails\Configuration;
+use StudioMitte\SentMails\Repository\MailRepository;
+use TYPO3\CMS\Core\Http\JsonResponse;
+
+class MailInformation implements MiddlewareInterface
+{
+
+    public function __construct(
+        protected readonly MailRepository $mailRepository,
+        protected readonly Configuration $configuration
+    )
+    {
+
+    }
+
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        if (!$this->isValidRequest($request)) {
+            return $handler->handle($request);
+        }
+
+        $response = new JsonResponse();
+        if (!$this->validateBasicAuth($request)) {
+            $response = $response->withAddedHeader('WWW-Authenticate', 'Basic realm="Access check"');
+        }
+
+        try {
+            $searchParam = $this->getSearchParam($request);
+            $response->setPayload($this->mailRepository->getMailsBySearch($searchParam));
+        } catch (\Exception $e) {
+            $response = $response->withStatus(400);
+            $response->setPayload(['error' => $e->getMessage()]);
+        }
+        return $response;
+    }
+
+    protected function getSearchParam(ServerRequestInterface $request): string
+    {
+        $searchParams = trim($request->getQueryParams()['search'] ?? '');
+        if (mb_strlen($searchParams) < 10) {
+            throw new \InvalidArgumentException('Search parameter must be at least 10 characters long', 1627980733);
+        }
+        return $searchParams;
+    }
+
+    protected function isValidRequest(ServerRequestInterface $request): bool
+    {
+        if (!$request->getUri()) {
+            return false;
+        }
+        $uri = $request->getUri();
+
+        return $uri->getPath() === '/api/mailinformation';
+    }
+
+    protected function validateBasicAuth(ServerRequestInterface $request): bool
+    {
+        $username = $request->getServerParams()['PHP_AUTH_USER'] ?? false;
+        $password = $request->getServerParams()['PHP_AUTH_PW'] ?? false;
+
+        return
+            $this->configuration->mailAPIUsername &&
+            $this->configuration->mailAPIPassword &&
+            $username === $this->configuration->mailAPIUsername &&
+            $password === $this->configuration->mailAPIPassword;
+    }
+
+}
diff --git a/Classes/Repository/MailRepository.php b/Classes/Repository/MailRepository.php
index edddff0..69babfa 100644
--- a/Classes/Repository/MailRepository.php
+++ b/Classes/Repository/MailRepository.php
@@ -3,13 +3,21 @@
 
 namespace StudioMitte\SentMails\Repository;
 
+use StudioMitte\SentMails\Configuration;
 use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\Database\Connection;
 use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 
 class MailRepository
 {
 
+    public function __construct(
+        protected readonly Configuration $configuration
+    )
+    {
+    }
+
     public function getMails(): array
     {
         $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable('tx_sentmail_mail');
@@ -26,5 +34,20 @@ public function getMailRow(int $id): array
         return (array)$row;
     }
 
+    public function getMailsBySearch(string $searchTerm): array
+    {
+        $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable('tx_sentmail_mail');
+        return $queryBuilder
+            ->select('is_sent')
+            ->addSelectLiteral('count(*) as count')
+            ->from('tx_sentmail_mail')
+            ->where(
+                $queryBuilder->expr()->gte('crdate', $queryBuilder->createNamedParameter((time() - $this->configuration->mailInformationMaxTime ), Connection::PARAM_INT)),
+                $queryBuilder->expr()->like('message', $queryBuilder->createNamedParameter('%' . $queryBuilder->escapeLikeWildcards($searchTerm) . '%'))
+            )
+            ->groupBy('is_sent')
+            ->executeQuery()->fetchAllAssociative();
+    }
+
 
 }
diff --git a/Configuration/RequestMiddlewares.php b/Configuration/RequestMiddlewares.php
new file mode 100644
index 0000000..52c562e
--- /dev/null
+++ b/Configuration/RequestMiddlewares.php
@@ -0,0 +1,14 @@
+<?php
+
+return [
+    'frontend' => [
+        'typo3/theme/logger' => [
+            'target' => \StudioMitte\SentMails\Middleware\MailInformation::class,
+            'before' => [
+                'typo3/cms-frontend/timetracker',
+            ],
+            'after' => [
+            ],
+        ],
+    ],
+];
diff --git a/Configuration/Services.yaml b/Configuration/Services.yaml
index a377d94..7b85e60 100644
--- a/Configuration/Services.yaml
+++ b/Configuration/Services.yaml
@@ -7,14 +7,25 @@ services:
   StudioMitte\SentMails\:
     resource: '../Classes/*'
 
+  StudioMitte\SentMails\Repository\MailRepository:
+    public: true
+
   StudioMitte\SentMails\EventListener\BeforeMailSentEventListener:
     tags:
       - name: event.listener
-        identifier: 'mail-sent-beforemailsent'
+        identifier: 'sent-mails/beforemailsent'
         event: TYPO3\CMS\Core\Mail\Event\BeforeMailerSentMessageEvent
 
   StudioMitte\SentMails\EventListener\AfterMailSentEventListener:
     tags:
       - name: event.listener
-        identifier: 'mail-sent-aftermailsent'
+        identifier: 'sent-mails/aftermailsent'
         event: TYPO3\CMS\Core\Mail\Event\AfterMailerSentMessageEvent
+
+  StudioMitte\SentMails\EventListener\MailMessageListener:
+    tags:
+      - name: event.listener
+        identifier: 'sent-mails/symfony/mailmessage-listener'
+        event: Symfony\Component\Mailer\Event\MessageEvent
+
+
diff --git a/Readme.md b/Readme.md
index 12dfe28..6ab782f 100644
--- a/Readme.md
+++ b/Readme.md
@@ -1,11 +1,12 @@
 # TYPO3 Extension `sent_mails`
 
-This extension provides a simple way to persist **all** sent mails in the database. 
-Using a dedicated backend module an user can:
+This extension provides a simple way to persist **all** sent mails in the database.
+Using a dedicated backend module a user can:
 
 * view the mail including plain & HTML view
 * resend the mail
 * forward the mail to a different email address
+* reject mails with a specific content
 
 ## Installation
 
@@ -15,4 +16,7 @@ This extension requires the usage of composer!
 composer req studiomitte/sent-mails
 ```
 
+## Mail-Information API
+
+Calling `/api/mailinformation?search=somecontent` will return a status information about the sent mails. Basic auth needs to be configured in the extension settings.
 
diff --git a/ext_conf_template.txt b/ext_conf_template.txt
new file mode 100644
index 0000000..e4ebf85
--- /dev/null
+++ b/ext_conf_template.txt
@@ -0,0 +1,8 @@
+# cat=Feature; type=string; label=Search terms leading to rejection:List of search terms (separated by ###) which lead to rejecting the mail sending process
+rejectBySearchTerms =
+
+# cat=Feature; type=string; label=Mail API Username:Provide the username for the mail API
+mailAPIUsername =
+
+# cat=Feature; type=string; label=Mail API Password:Provide the password for the mail API
+mailAPIPassword =