diff --git a/src/app/Http/Controllers/API/V4/UsersController.php b/src/app/Http/Controllers/API/V4/UsersController.php
--- a/src/app/Http/Controllers/API/V4/UsersController.php
+++ b/src/app/Http/Controllers/API/V4/UsersController.php
@@ -629,14 +629,14 @@
             return \trans('validation.entryinvalid', ['attribute' => $attribute]);
         }
 
-        list($login, $domain) = explode('@', $email);
+        list($login, $domain) = explode('@', Str::lower($email));
 
         if (strlen($login) === 0 || strlen($domain) === 0) {
             return \trans('validation.entryinvalid', ['attribute' => $attribute]);
         }
 
         // Check if domain exists
-        $domain = Domain::where('namespace', Str::lower($domain))->first();
+        $domain = Domain::where('namespace', $domain)->first();
 
         if (empty($domain)) {
             return \trans('validation.domaininvalid');
diff --git a/src/app/Observers/DomainObserver.php b/src/app/Observers/DomainObserver.php
--- a/src/app/Observers/DomainObserver.php
+++ b/src/app/Observers/DomainObserver.php
@@ -24,6 +24,8 @@
             }
         }
 
+        $domain->namespace = \strtolower($domain->namespace);
+
         $domain->status |= Domain::STATUS_NEW | Domain::STATUS_ACTIVE;
     }
 
diff --git a/src/app/Observers/UserObserver.php b/src/app/Observers/UserObserver.php
--- a/src/app/Observers/UserObserver.php
+++ b/src/app/Observers/UserObserver.php
@@ -32,6 +32,8 @@
             }
         }
 
+        $user->email = \strtolower($user->email);
+
         // only users that are not imported get the benefit of the doubt.
         $user->status |= User::STATUS_NEW | User::STATUS_ACTIVE;
 
diff --git a/src/database/seeds/local/UserSeeder.php b/src/database/seeds/local/UserSeeder.php
--- a/src/database/seeds/local/UserSeeder.php
+++ b/src/database/seeds/local/UserSeeder.php
@@ -136,8 +136,7 @@
             ]
         );
 
-        $jeroen->role = "admin";
-
+        $jeroen->role = 'admin';
         $jeroen->save();
     }
 }
diff --git a/src/tests/Feature/DomainTest.php b/src/tests/Feature/DomainTest.php
--- a/src/tests/Feature/DomainTest.php
+++ b/src/tests/Feature/DomainTest.php
@@ -48,6 +48,27 @@
     }
 
     /**
+     * Test domain create/creating observer
+     */
+    public function testCreate(): void
+    {
+        Queue::fake();
+
+        $domain = Domain::create([
+                'namespace' => 'GMAIL.COM',
+                'status' => Domain::STATUS_NEW,
+                'type' => Domain::TYPE_EXTERNAL,
+        ]);
+
+        $result = Domain::where('namespace', 'gmail.com')->first();
+
+        $this->assertSame('gmail.com', $result->namespace);
+        $this->assertSame($domain->id, $result->id);
+        $this->assertSame($domain->type, $result->type);
+        $this->assertSame(Domain::STATUS_NEW | Domain::STATUS_ACTIVE, $result->status);
+    }
+
+    /**
      * Test domain creating jobs
      */
     public function testCreateJobs(): void
diff --git a/src/tests/Feature/UserTest.php b/src/tests/Feature/UserTest.php
--- a/src/tests/Feature/UserTest.php
+++ b/src/tests/Feature/UserTest.php
@@ -56,9 +56,63 @@
     }
 
     /**
+     * Verify a wallet assigned a controller is among the accounts of the assignee.
+     */
+    public function testAccounts(): void
+    {
+        $userA = $this->getTestUser('UserAccountA@UserAccount.com');
+        $userB = $this->getTestUser('UserAccountB@UserAccount.com');
+
+        $this->assertTrue($userA->wallets()->count() == 1);
+
+        $userA->wallets()->each(
+            function ($wallet) use ($userB) {
+                $wallet->addController($userB);
+            }
+        );
+
+        $this->assertTrue($userB->accounts()->get()[0]->id === $userA->wallets()->get()[0]->id);
+    }
+
+    public function testCanDelete(): void
+    {
+        $this->markTestIncomplete();
+    }
+
+    public function testCanRead(): void
+    {
+        $this->markTestIncomplete();
+    }
+
+    public function testCanUpdate(): void
+    {
+        $this->markTestIncomplete();
+    }
+
+    /**
+     * Test user create/creating observer
+     */
+    public function testCreate(): void
+    {
+        Queue::fake();
+
+        $domain = \config('app.domain');
+
+        $user = User::create([
+                'email' => 'USER-test@' . \strtoupper($domain)
+        ]);
+
+        $result = User::where('email', 'user-test@' . $domain)->first();
+
+        $this->assertSame('user-test@' . $domain, $result->email);
+        $this->assertSame($user->id, $result->id);
+        $this->assertSame(User::STATUS_NEW | User::STATUS_ACTIVE, $result->status);
+    }
+
+    /**
      * Verify user creation process
      */
-    public function testUserCreateJob(): void
+    public function testCreateJobs(): void
     {
         // Fake the queue, assert that no jobs were pushed...
         Queue::fake();
@@ -96,45 +150,6 @@
     }
 
     /**
-     * Verify a wallet assigned a controller is among the accounts of the assignee.
-     */
-    public function testListUserAccounts(): void
-    {
-        $userA = $this->getTestUser('UserAccountA@UserAccount.com');
-        $userB = $this->getTestUser('UserAccountB@UserAccount.com');
-
-        $this->assertTrue($userA->wallets()->count() == 1);
-
-        $userA->wallets()->each(
-            function ($wallet) use ($userB) {
-                $wallet->addController($userB);
-            }
-        );
-
-        $this->assertTrue($userB->accounts()->get()[0]->id === $userA->wallets()->get()[0]->id);
-    }
-
-    public function testAccounts(): void
-    {
-        $this->markTestIncomplete();
-    }
-
-    public function testCanDelete(): void
-    {
-        $this->markTestIncomplete();
-    }
-
-    public function testCanRead(): void
-    {
-        $this->markTestIncomplete();
-    }
-
-    public function testCanUpdate(): void
-    {
-        $this->markTestIncomplete();
-    }
-
-    /**
      * Tests for User::domains()
      */
     public function testDomains(): void