diff --git a/app/Livewire/Ui/System/SettingsForm.php b/app/Livewire/Ui/System/SettingsForm.php
index d54b5cc..9e7e201 100644
--- a/app/Livewire/Ui/System/SettingsForm.php
+++ b/app/Livewire/Ui/System/SettingsForm.php
@@ -227,7 +227,21 @@ class SettingsForm extends Component
 
     private function syncSysmailDomain(): void
     {
-        $platformBase = strtolower(config('mailpool.platform_zone', env('BASE_DOMAIN', '')));
+        // BASE_DOMAIN aus config, env oder mail_domain ableiten
+        $platformBase = strtolower((string) config('mailpool.platform_zone', ''));
+        if (!$platformBase || $platformBase === 'example.com') {
+            $platformBase = strtolower((string) env('BASE_DOMAIN', ''));
+        }
+        if (!$platformBase || $platformBase === 'example.com') {
+            // Fallback: aus mail_domain den Hostnamen ohne ersten Subdomain-Teil
+            $mailDomain = strtolower(trim((string) Setting::get('mail_domain', '')));
+            if ($mailDomain) {
+                $parts = explode('.', $mailDomain);
+                $platformBase = count($parts) > 2
+                    ? implode('.', array_slice($parts, 1))
+                    : $mailDomain;
+            }
+        }
         if (!$platformBase || $platformBase === 'example.com') return;
 
         $systemSub  = strtolower(config('mailpool.platform_system_zone', 'sysmail'));
@@ -253,8 +267,16 @@ class SettingsForm extends Component
                 '--class' => 'Database\\Seeders\\SystemDomainSeeder',
                 '--force' => true,
             ]);
+            \Illuminate\Support\Facades\Log::info('SystemDomainSeeder ok', ['fqdn' => $expectedFqdn]);
         } catch (\Throwable $e) {
-            \Illuminate\Support\Facades\Log::error('SystemDomainSeeder failed', ['error' => $e->getMessage()]);
+            \Illuminate\Support\Facades\Log::error('SystemDomainSeeder failed', [
+                'fqdn'  => $expectedFqdn,
+                'error' => $e->getMessage(),
+                'trace' => $e->getTraceAsString(),
+            ]);
+            $this->dispatch('toast', type: 'warn', badge: 'Sysmail',
+                title: 'System-Domain konnte nicht angelegt werden',
+                text: $e->getMessage(), duration: 8000);
         }
     }