diff --git a/src/lib/dyn_dns/MailinaboxProvider.php b/src/lib/dyn_dns/MailinaboxProvider.php
new file mode 100644
index 0000000..8ee92cc
--- /dev/null
+++ b/src/lib/dyn_dns/MailinaboxProvider.php
@@ -0,0 +1,46 @@
+<?php
+
+require_once __DIR__ . '/BaseProvider.php';
+
+class MailinaboxProvider extends BaseProvider {
+    public function updateIp(string $ip): bool {
+        $email = $this->credentials['mabEmail'] ?? null;
+        $apiKey = $this->credentials['mabApiKey'] ?? null;
+        $force = !empty($this->credentials['mabForce']) && $this->credentials['mabForce'] == '1';
+
+        if (!$email || !$apiKey) {
+            $this->logger->error("Missing credentials for Mail‑in‑a‑Box DDNS: {$this->domain}");
+            return false;
+        }
+
+        $url = "https://{$this->credentials['mabHost']}/admin/dns/update";
+        $postFields = http_build_query([
+            'force' => $force ? 1 : 0,
+        ]);
+
+        $ch = curl_init($url);
+        curl_setopt_array($ch, [
+            CURLOPT_RETURNTRANSFER => true,
+            CURLOPT_USERPWD => "$email:$apiKey",
+            CURLOPT_HTTPAUTH => CURLAUTH_BASIC,
+            CURLOPT_POST => true,
+            CURLOPT_POSTFIELDS => $postFields,
+            CURLOPT_HTTPHEADER => ["Content-Type: application/x-www-form-urlencoded"],
+        ]);
+
+        $resp = curl_exec($ch);
+        if ($resp === false) {
+            $this->logger->error("Mail‑in‑a‑Box /dns/update request failed: {$this->domain}");
+            return false;
+        }
+        curl_close($ch);
+
+        if (strpos($resp, 'updated DNS:') !== false) {
+            $this->logger->info("Mail‑in‑a‑Box DDNS updated for {$this->domain}: $resp");
+            return true;
+        } else {
+            $this->logger->error("Mail‑in‑a‑Box DDNS update failed for {$this->domain}: $resp");
+            return false;
+        }
+    }
+}
diff --git a/src/lib/dyn_dns_update.php b/src/lib/dyn_dns_update.php
index 862c770..5db1ea1 100644
--- a/src/lib/dyn_dns_update.php
+++ b/src/lib/dyn_dns_update.php
@@ -7,6 +7,7 @@
 require_once __DIR__ . '/dyn_dns/StratoProvider.php';
 require_once __DIR__ . '/dyn_dns/NamecheapProvider.php';
 require_once __DIR__ . '/dyn_dns/CloudflareProvider.php';
+require_once __DIR__ . '/dyn_dns/MailinaboxProvider.php';
 require_once __DIR__ . '/dyn_dns/HetznerProvider.php';
 
 $domainManager = new PersistentEntityManager(Domain::class, $logger, DB, 'domains');
@@ -34,6 +35,7 @@
         'strato'     => StratoProvider::class,
         'namecheap'  => NamecheapProvider::class,
         'cloudflare' => CloudflareProvider::class,
+        'mailinabox' => MailinaboxProvider::class,
         'hetzner' => HetznerProvider::class,
         default      => null,
     };
diff --git a/src/public/domains.php b/src/public/domains.php
index ebcac4c..4288572 100644
--- a/src/public/domains.php
+++ b/src/public/domains.php
@@ -219,6 +219,7 @@
       <option value="strato">Strato</option>
       <option value="namecheap">Namecheap</option>
       <option value="cloudflare">Cloudflare</option>
+      <option value="mailinabox">Mailinabox</option>
       <option value="hetzner">Hetzner</option>
     </select>
 
@@ -350,6 +351,12 @@
       { label: 'API Token', id: 'cfApiToken', type: 'text' },
       { label: 'Zone ID', id: 'cfZoneId', type: 'text' }
     ],
+    mailinabox: [
+      { label: 'Host (box.example.com)', id: 'mabHost', type: 'text' },
+      { label: 'Email (admin user)', id: 'mabEmail', type: 'text' },
+      { label: 'API Key', id: 'mabApiKey', type: 'password' },
+      { label: 'Force Update (0 or 1)', id: 'mabForce', type: 'text' }
+    ],
     hetzner: [
       { label: 'API Token', id: 'hetznerApiToken', type: 'text' },
       { label: 'Zone ID', id: 'hetznerZoneId', type: 'text' }