diff --git a/src/app/Jobs/CommonJob.php b/src/app/Jobs/CommonJob.php
index fa9d0831..ce931614 100644
--- a/src/app/Jobs/CommonJob.php
+++ b/src/app/Jobs/CommonJob.php
@@ -1,140 +1,144 @@
 <?php
 
 namespace App\Jobs;
 
 use Illuminate\Bus\Queueable;
 use Illuminate\Contracts\Queue\ShouldQueue;
 use Illuminate\Foundation\Bus\Dispatchable;
 use Illuminate\Queue\InteractsWithQueue;
 
 /**
  * The abstract \App\Jobs\DomainJob implements the logic needed for all dispatchable Jobs related to
  * \App\Domain objects.
  *
  * ```php
  * $job = new \App\Jobs\Domain\CreateJob($domainId);
  * $job->handle();
  * ```
  */
 abstract class CommonJob implements ShouldQueue
 {
     use Dispatchable;
     use InteractsWithQueue;
     use Queueable;
 
     /**
      * The failure message.
      *
      * @var string
      */
     public $failureMessage;
 
     /**
      * The job deleted state.
      *
      * @var bool
      */
     protected $isDeleted = false;
 
     /**
      * The job released state.
      *
      * @var bool
      */
     protected $isReleased = false;
 
     /**
      * The number of tries for this Job.
      *
      * @var int
      */
     public $tries = 5;
 
     /**
      * Execute the job.
      *
      * @return void
      */
     abstract public function handle();
 
     /**
      * Delete the job from the queue.
      *
      * @return void
      */
     public function delete()
     {
         // We need this for testing purposes
         $this->isDeleted = true;
 
         // @phpstan-ignore-next-line
         if ($this->job) {
             $this->job->delete();
         }
     }
 
     /**
      * Delete the job, call the "failed" method, and raise the failed job event.
      *
      * @param \Throwable|null $e An Exception
      *
      * @return void
      */
     public function fail($e = null)
     {
         // Save the message, for testing purposes
         $this->failureMessage = $e->getMessage();
 
         // @phpstan-ignore-next-line
         if ($this->job) {
             $this->job->fail($e);
         }
     }
 
     /**
      * Check if the job has failed
      *
      * @return bool
      */
     public function hasFailed(): bool
     {
         return $this->failureMessage !== null;
     }
 
     /**
      * Release the job back into the queue.
      *
      * @param int $delay Time in seconds
      * @return void
      */
     public function release($delay = 0)
     {
         // We need this for testing purposes
         $this->isReleased = true;
 
         // @phpstan-ignore-next-line
         if ($this->job) {
             $this->job->release($delay);
+        } else {
+            // $this->job is only set when the job is dispatched, not if manually executed by calling handle().
+            // When manually executed, release() does nothing, and we thus throw an exception.
+            throw new \Exception("Attempted to release a manually executed job");
         }
     }
 
     /**
      * Determine if the job has been deleted.
      *
      * @return bool
      */
     public function isDeleted(): bool
     {
         return $this->isDeleted;
     }
 
     /**
      * Check if the job was released
      *
      * @return bool
      */
     public function isReleased(): bool
     {
         return $this->isReleased;
     }
 }
diff --git a/src/tests/Feature/Jobs/Domain/CreateTest.php b/src/tests/Feature/Jobs/Domain/CreateTest.php
index 0e5989d8..da341552 100644
--- a/src/tests/Feature/Jobs/Domain/CreateTest.php
+++ b/src/tests/Feature/Jobs/Domain/CreateTest.php
@@ -1,74 +1,75 @@
 <?php
 
 namespace Tests\Feature\Jobs\Domain;
 
 use App\Domain;
 use Illuminate\Support\Facades\Queue;
 use Tests\TestCase;
 
 class CreateTest extends TestCase
 {
     /**
      * {@inheritDoc}
      */
     public function setUp(): void
     {
         parent::setUp();
 
         $this->deleteTestDomain('domain-create-test.com');
     }
 
     public function tearDown(): void
     {
         $this->deleteTestDomain('domain-create-test.com');
 
         parent::tearDown();
     }
 
     /**
      * Test job handle
      *
      * @group ldap
      */
     public function testHandle(): void
     {
         $domain = $this->getTestDomain(
             'domain-create-test.com',
             [
                 'status' => Domain::STATUS_NEW,
                 'type' => Domain::TYPE_EXTERNAL,
             ]
         );
 
         $this->assertFalse($domain->isLdapReady());
 
         // Fake the queue, assert that no jobs were pushed...
         Queue::fake();
         Queue::assertNothingPushed();
 
         $job = new \App\Jobs\Domain\CreateJob($domain->id);
         $job->handle();
 
         $this->assertTrue($domain->fresh()->isLdapReady());
 
         Queue::assertPushed(\App\Jobs\Domain\VerifyJob::class, 1);
 
         Queue::assertPushed(
             \App\Jobs\Domain\VerifyJob::class,
             function ($job) use ($domain) {
                 $domainId = TestCase::getObjectProperty($job, 'domainId');
                 $domainNamespace = TestCase::getObjectProperty($job, 'domainNamespace');
 
                 return $domainId === $domain->id &&
                     $domainNamespace === $domain->namespace;
             }
         );
 
         // Test job releasing on unknown identifier
+        $this->expectException(\Exception::class);
         $job = new \App\Jobs\Domain\CreateJob(123);
         $job->handle();
 
         $this->assertTrue($job->isReleased());
         $this->assertFalse($job->hasFailed());
     }
 }
diff --git a/src/tests/Feature/Jobs/Group/CreateTest.php b/src/tests/Feature/Jobs/Group/CreateTest.php
index 99b87a3b..8b8e3f75 100644
--- a/src/tests/Feature/Jobs/Group/CreateTest.php
+++ b/src/tests/Feature/Jobs/Group/CreateTest.php
@@ -1,50 +1,51 @@
 <?php
 
 namespace Tests\Feature\Jobs\Group;
 
 use App\Group;
 use Tests\TestCase;
 
 class CreateTest extends TestCase
 {
     /**
      * {@inheritDoc}
      */
     public function setUp(): void
     {
         parent::setUp();
 
         $this->deleteTestGroup('group@kolab.org');
     }
 
     public function tearDown(): void
     {
         $this->deleteTestGroup('group@kolab.org');
 
         parent::tearDown();
     }
 
     /**
      * Test job handle
      *
      * @group ldap
      */
     public function testHandle(): void
     {
         $group = $this->getTestGroup('group@kolab.org', ['members' => []]);
 
         $this->assertFalse($group->isLdapReady());
 
         $job = new \App\Jobs\Group\CreateJob($group->id);
         $job->handle();
 
         $this->assertTrue($group->fresh()->isLdapReady());
 
         // Test non-existing group ID
+        $this->expectException(\Exception::class);
         $job = new \App\Jobs\Group\CreateJob(123);
         $job->handle();
 
         $this->assertTrue($job->isReleased());
         $this->assertFalse($job->hasFailed());
     }
 }
diff --git a/src/tests/Feature/Jobs/Resource/CreateTest.php b/src/tests/Feature/Jobs/Resource/CreateTest.php
index 496b8228..b7ebfe9e 100644
--- a/src/tests/Feature/Jobs/Resource/CreateTest.php
+++ b/src/tests/Feature/Jobs/Resource/CreateTest.php
@@ -1,83 +1,84 @@
 <?php
 
 namespace Tests\Feature\Jobs\Resource;
 
 use App\Resource;
 use Illuminate\Support\Facades\Queue;
 use Tests\TestCase;
 
 class CreateTest extends TestCase
 {
     /**
      * {@inheritDoc}
      */
     public function setUp(): void
     {
         parent::setUp();
 
         $this->deleteTestResource('resource-test@' . \config('app.domain'));
     }
 
     public function tearDown(): void
     {
         $this->deleteTestResource('resource-test@' . \config('app.domain'));
 
         parent::tearDown();
     }
 
     /**
      * Test job handle
      *
      * @group ldap
      */
     public function testHandle(): void
     {
         Queue::fake();
 
         // Test unknown resource
+        $this->expectException(\Exception::class);
         $job = new \App\Jobs\Resource\CreateJob(123);
         $job->handle();
 
         $this->assertTrue($job->isReleased());
         $this->assertFalse($job->hasFailed());
 
         $resource = $this->getTestResource('resource-test@' . \config('app.domain'));
 
         $this->assertFalse($resource->isLdapReady());
 
         // Test resource creation
         $job = new \App\Jobs\Resource\CreateJob($resource->id);
         $job->handle();
 
         $this->assertTrue($resource->fresh()->isLdapReady());
         $this->assertFalse($job->hasFailed());
 
         // Test job failures
         $job = new \App\Jobs\Resource\CreateJob($resource->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("Resource {$resource->id} is already marked as ldap-ready.", $job->failureMessage);
 
         $resource->status |= Resource::STATUS_DELETED;
         $resource->save();
 
         $job = new \App\Jobs\Resource\CreateJob($resource->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("Resource {$resource->id} is marked as deleted.", $job->failureMessage);
 
         $resource->status ^= Resource::STATUS_DELETED;
         $resource->save();
         $resource->delete();
 
         $job = new \App\Jobs\Resource\CreateJob($resource->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("Resource {$resource->id} is actually deleted.", $job->failureMessage);
 
         // TODO: Test failures on domain sanity checks
     }
 }
diff --git a/src/tests/Feature/Jobs/SharedFolder/CreateTest.php b/src/tests/Feature/Jobs/SharedFolder/CreateTest.php
index f9aca4b5..389f5ab4 100644
--- a/src/tests/Feature/Jobs/SharedFolder/CreateTest.php
+++ b/src/tests/Feature/Jobs/SharedFolder/CreateTest.php
@@ -1,83 +1,84 @@
 <?php
 
 namespace Tests\Feature\Jobs\SharedFolder;
 
 use App\SharedFolder;
 use Illuminate\Support\Facades\Queue;
 use Tests\TestCase;
 
 class CreateTest extends TestCase
 {
     /**
      * {@inheritDoc}
      */
     public function setUp(): void
     {
         parent::setUp();
 
         $this->deleteTestSharedFolder('folder-test@' . \config('app.domain'));
     }
 
     public function tearDown(): void
     {
         $this->deleteTestSharedFolder('folder-test@' . \config('app.domain'));
 
         parent::tearDown();
     }
 
     /**
      * Test job handle
      *
      * @group ldap
      */
     public function testHandle(): void
     {
         Queue::fake();
 
         // Test unknown folder
+        $this->expectException(\Exception::class);
         $job = new \App\Jobs\SharedFolder\CreateJob(123);
         $job->handle();
 
         $this->assertTrue($job->isReleased());
         $this->assertFalse($job->hasFailed());
 
         $folder = $this->getTestSharedFolder('folder-test@' . \config('app.domain'));
 
         $this->assertFalse($folder->isLdapReady());
 
         // Test shared folder creation
         $job = new \App\Jobs\SharedFolder\CreateJob($folder->id);
         $job->handle();
 
         $this->assertTrue($folder->fresh()->isLdapReady());
         $this->assertFalse($job->hasFailed());
 
         // Test job failures
         $job = new \App\Jobs\SharedFolder\CreateJob($folder->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("Shared folder {$folder->id} is already marked as ldap-ready.", $job->failureMessage);
 
         $folder->status |= SharedFolder::STATUS_DELETED;
         $folder->save();
 
         $job = new \App\Jobs\SharedFolder\CreateJob($folder->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("Shared folder {$folder->id} is marked as deleted.", $job->failureMessage);
 
         $folder->status ^= SharedFolder::STATUS_DELETED;
         $folder->save();
         $folder->delete();
 
         $job = new \App\Jobs\SharedFolder\CreateJob($folder->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("Shared folder {$folder->id} is actually deleted.", $job->failureMessage);
 
         // TODO: Test failures on domain sanity checks
     }
 }
diff --git a/src/tests/Feature/Jobs/User/CreateTest.php b/src/tests/Feature/Jobs/User/CreateTest.php
index fcc696e7..5dc8412c 100644
--- a/src/tests/Feature/Jobs/User/CreateTest.php
+++ b/src/tests/Feature/Jobs/User/CreateTest.php
@@ -1,78 +1,79 @@
 <?php
 
 namespace Tests\Feature\Jobs\User;
 
 use App\User;
 use Tests\TestCase;
 
 class CreateTest extends TestCase
 {
     /**
      * {@inheritDoc}
      */
     public function setUp(): void
     {
         parent::setUp();
 
         $this->deleteTestUser('new-job-user@' . \config('app.domain'));
     }
 
     public function tearDown(): void
     {
         $this->deleteTestUser('new-job-user@' . \config('app.domain'));
 
         parent::tearDown();
     }
 
     /**
      * Test job handle
      *
      * @group ldap
      */
     public function testHandle(): void
     {
         $user = $this->getTestUser('new-job-user@' . \config('app.domain'));
 
         $this->assertFalse($user->isLdapReady());
 
         $job = new \App\Jobs\User\CreateJob($user->id);
         $job->handle();
 
         $this->assertTrue($user->fresh()->isLdapReady());
         $this->assertFalse($job->hasFailed());
 
         // Test job failures
         $job = new \App\Jobs\User\CreateJob($user->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("User {$user->id} is already marked as ldap-ready.", $job->failureMessage);
 
         $user->status |= User::STATUS_DELETED;
         $user->save();
 
         $job = new \App\Jobs\User\CreateJob($user->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("User {$user->id} is marked as deleted.", $job->failureMessage);
 
         $user->status ^= User::STATUS_DELETED;
         $user->save();
         $user->delete();
 
         $job = new \App\Jobs\User\CreateJob($user->id);
         $job->handle();
 
         $this->assertTrue($job->hasFailed());
         $this->assertSame("User {$user->id} is actually deleted.", $job->failureMessage);
 
         // TODO: Test failures on domain sanity checks
 
+        $this->expectException(\Exception::class);
         $job = new \App\Jobs\User\CreateJob(123);
         $job->handle();
 
         $this->assertTrue($job->isReleased());
         $this->assertFalse($job->hasFailed());
     }
 }