diff --git a/index.php b/index.php
index c1c1587..ba03de4 100644
--- a/index.php
+++ b/index.php
@@ -17,6 +17,40 @@ function containsHeaderInjection(string $value): bool
     return (bool) preg_match('/[\r\n]/', $value);
 }
 
+// --- Send email via AgentMail API ---
+function sendContactEmail(string $subject, string $body, string $replyToEmail, string $replyToName): bool
+{
+    $apiKey = getenv('AGENTMAIL_API_KEY') ?: '';
+    if ($apiKey === '') {
+        return false;
+    }
+
+    $apiUrl = 'https://api.agentmail.to/v0/inboxes/max-kies-media-ai-assistent@agentmail.to/messages/send';
+    $payload = json_encode([
+        'to'         => ['mki@kies-media.de'],
+        'subject'    => $subject,
+        'text'       => $body,
+        'reply_to'   => $replyToEmail,
+    ]);
+
+    $ch = curl_init($apiUrl);
+    curl_setopt_array($ch, [
+        CURLOPT_POST           => true,
+        CURLOPT_POSTFIELDS     => $payload,
+        CURLOPT_RETURNTRANSFER => true,
+        CURLOPT_TIMEOUT        => 10,
+        CURLOPT_HTTPHEADER     => [
+            'Authorization: Bearer ' . $apiKey,
+            'Content-Type: application/json',
+        ],
+    ]);
+    $response = curl_exec($ch);
+    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+    curl_close($ch);
+
+    return $httpCode >= 200 && $httpCode < 300;
+}
+
 // --- Form processing ---
 $formErrors = [];
 $formSuccess = false;
@@ -69,9 +103,8 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             $formErrors[] = 'Bitte warten Sie einen Moment vor der nächsten Anfrage.';
         }
 
-        // Send email if no errors
+        // Send email via AgentMail API if no errors
         if (empty($formErrors)) {
-            $to      = 'mki@kies-media.de';
             $subject = 'Kontaktanfrage: ' . $formData['interest'];
             $body    = "Von: {$formData['fname']} {$formData['lname']}\n"
                      . "E-Mail: {$formData['email']}\n";
@@ -81,12 +114,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             $body .= "Anliegen: {$formData['interest']}\n\n"
                      . $formData['message'];
 
-            $headers  = "From: {$formData['email']}\r\n";
-            $headers .= "Reply-To: {$formData['email']}\r\n";
-            $headers .= "Content-Type: text/plain; charset=UTF-8\r\n";
-            $headers .= "X-Mailer: PHP/" . phpversion();
-
-            $mailSent = mail($to, $subject, $body, $headers);
+            $mailSent = sendContactEmail($subject, $body, $formData['email'], $formData['fname'] . ' ' . $formData['lname']);
 
             if ($mailSent) {
                 $formSuccess = true;