diff --git a/.env.develop b/.env.develop
index 968fd4b..07b491f 100644
--- a/.env.develop
+++ b/.env.develop
@@ -3,21 +3,22 @@
 # composer: Set cache directory
 COMPOSER_CACHE_DIR=./.composer
 
-# MariaDB container
+# Environment variables for MariaDB container
 MYSQL_RANDOM_ROOT_PASSWORD=yes
 MYSQL_DATABASE=mailusers
 MYSQL_USER=mailaccountadmin
 MYSQL_PASSWORD=mailaccountadmin
 
 # App settings
+APP_ENV=development
 APP_DEBUG=true
+APP_TIMEZONE=Europe/Berlin
 
-# - Disable Twig cache
+# Disable Twig cache
 TWIG_CACHE_DIR=
-TWIG_STRICT=true
 
-# - Database credentials
+# Database credentials
 DB_HOST=db
 DB_DATABASE=mailusers
-DB_USER=mailaccountadmin
+DB_USERNAME=mailaccountadmin
 DB_PASSWORD=mailaccountadmin
diff --git a/Dockerfile b/Dockerfile
index 695e69b..9f9d176 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,8 +18,6 @@ RUN cp $PHP_INI_DIR/php.ini-development $PHP_INI_DIR/php.ini && \
     pecl install xdebug && \
     docker-php-ext-enable xdebug
 
-ENV APP_ENV=development
-
 # TODO: production image untested
 #FROM base AS production
 #
diff --git a/public/index.php b/public/index.php
index 37641db..10628de 100644
--- a/public/index.php
+++ b/public/index.php
@@ -3,19 +3,19 @@ declare(strict_types=1);
 
 require_once __DIR__ . '/../vendor/autoload.php';
 
+use MailAccountAdmin\Config\Loaders\EnvConfigLoader;
 use MailAccountAdmin\Dependencies;
 use MailAccountAdmin\Middlewares;
 use MailAccountAdmin\Routes;
-use MailAccountAdmin\Settings;
 use Slim\Factory\AppFactory;
 
 session_start();
 
-$settings = new Settings();
-$container = Dependencies::createContainer($settings);
+$config = EnvConfigLoader::loadFromEnv();
+$container = Dependencies::createContainer($config);
 $app = AppFactory::createFromContainer($container);
 
-Middlewares::setMiddlewares($app, $settings);
+Middlewares::setMiddlewares($app, $config);
 Routes::setRoutes($app);
 
 $app->run();
diff --git a/src/Config/AppConfig.php b/src/Config/AppConfig.php
new file mode 100644
index 0000000..4735a10
--- /dev/null
+++ b/src/Config/AppConfig.php
@@ -0,0 +1,92 @@
+<?php
+declare(strict_types=1);
+
+namespace MailAccountAdmin\Config;
+
+class AppConfig
+{
+    // App settings
+    protected string $appTitle = 'MailAccountAdmin';
+    protected string $environment = 'production';
+    protected bool $debug = false;
+    protected string $timezone;
+    protected string $dateTimeFormat = 'r';
+
+    // Twig settings
+    protected ?string $twigCacheDir = null;
+
+    // Database settings
+    protected string $databaseHost = 'localhost';
+    protected int $databasePort = 3306;
+    protected string $databaseName = '';
+    protected string $databaseUsername = '';
+    protected string $databasePassword = '';
+
+    protected function __construct()
+    {
+        // Set default timezone from php.ini
+        $this->timezone = ini_get('date.timezone') ?: 'UTC';
+    }
+
+    public static function createFromArray(array $configArray): self
+    {
+        $config = new self();
+
+        foreach ($configArray as $key => $value) {
+            assert(property_exists($config, $key));
+
+            if ($value !== null) {
+                $config->$key = $value;
+            }
+        }
+
+        return $config;
+    }
+
+    public function getAppTitle(): string
+    {
+        return $this->appTitle;
+    }
+
+    public function getAppEnvironment(): string
+    {
+        return $this->environment;
+    }
+
+    public function isDebugMode(): bool
+    {
+        return $this->debug;
+    }
+
+    public function getTimezone(): string
+    {
+        return $this->timezone;
+    }
+
+    public function getDateTimeFormat(): string
+    {
+        // Specify datetime format (https://www.php.net/manual/en/datetime.format.php)
+        // Default value "r": RFC 2822 formatted date (Thu, 21 Dec 2000 16:01:07 +0200)
+        return $this->dateTimeFormat;
+    }
+
+    public function getTwigSettings(): array
+    {
+        return [
+            'cache' => $this->twigCacheDir ?: false,
+            'debug' => $this->isDebugMode(),
+            'strict_variables' => $this->isDebugMode(),
+        ];
+    }
+
+    public function getDatabaseSettings(): array
+    {
+        return [
+            'host' => $this->databaseHost,
+            'port' => $this->databasePort,
+            'dbname' => $this->databaseName,
+            'username' => $this->databaseUsername,
+            'password' => $this->databasePassword,
+        ];
+    }
+}
diff --git a/src/Config/Loaders/EnvConfigLoader.php b/src/Config/Loaders/EnvConfigLoader.php
new file mode 100644
index 0000000..06378f8
--- /dev/null
+++ b/src/Config/Loaders/EnvConfigLoader.php
@@ -0,0 +1,31 @@
+<?php
+declare(strict_types=1);
+
+namespace MailAccountAdmin\Config\Loaders;
+
+use MailAccountAdmin\Config\AppConfig;
+
+class EnvConfigLoader
+{
+    public static function loadFromEnv(): AppConfig
+    {
+        return AppConfig::createFromArray([
+            // App settings
+            'appTitle' => getenv('APP_TITLE') ?: null,
+            'environment' => getenv('APP_ENV') ?: null,
+            'debug' => getenv('APP_DEBUG') === 'true' ? true : null,
+            'timezone' => getenv('APP_TIMEZONE') ?: null,
+            'dateTimeFormat' => getenv('APP_DATE_TIME_FORMAT') ?: null,
+
+            // Twig settings
+            'twigCacheDir' => getenv('TWIG_CACHE_DIR') ?: null,
+
+            // Database settings
+            'databaseHost' => getenv('DB_HOST') ?: null,
+            'databasePort' => (int)getenv('DB_PORT') ?: null,
+            'databaseName' => getenv('DB_DATABASE') ?: null,
+            'databaseUsername' => getenv('DB_USERNAME') ?: null,
+            'databasePassword' => getenv('DB_PASSWORD') ?: null,
+        ]);
+    }
+}
diff --git a/src/Dependencies.php b/src/Dependencies.php
index 94c0d64..30dd467 100644
--- a/src/Dependencies.php
+++ b/src/Dependencies.php
@@ -7,6 +7,7 @@ use DI\Container;
 use MailAccountAdmin\Common\PasswordHelper;
 use MailAccountAdmin\Common\SessionHelper;
 use MailAccountAdmin\Common\UserHelper;
+use MailAccountAdmin\Config\AppConfig;
 use MailAccountAdmin\Frontend\Accounts\AccountController;
 use MailAccountAdmin\Frontend\Accounts\AccountHandler;
 use MailAccountAdmin\Frontend\Domains\DomainController;
@@ -23,43 +24,43 @@ use Twig\Extension\CoreExtension as TwigCoreExtension;
 
 class Dependencies
 {
-    public const SETTINGS = 'settings';
+    public const CONFIG = 'config';
     public const TWIG = 'view';
     private const TWIG_TEMPLATE_DIR = __DIR__ . '/../templates';
     public const DATABASE = 'database';
 
-    public static function createContainer(Settings $settings): Container
+    public static function createContainer(AppConfig $config): Container
     {
         $container = new Container();
 
-        // App settings
-        $container->set(self::SETTINGS, $settings);
+        // App configuration
+        $container->set(self::CONFIG, $config);
 
         // App information
         $container->set(AppInfo::class, function (ContainerInterface $c) {
-            /** @var Settings $settings */
-            $settings = $c->get(self::SETTINGS);
-            $versionHelper = new VersionHelper();
+            /** @var AppConfig $config */
+            $config = $c->get(self::CONFIG);
+            $versionHelper = new VersionHelper($config);
 
             return new AppInfo(
-                $settings->getAppTitle(),
+                $config->getAppTitle(),
                 $versionHelper->getAppVersion(),
             );
         });
 
         // Twig template engine
         $container->set(self::TWIG, function (ContainerInterface $c) {
-            /** @var Settings $settings */
-            $settings = $c->get(self::SETTINGS);
+            /** @var AppConfig $config */
+            $config = $c->get(self::CONFIG);
 
             // Create Twig view
-            $twig = Twig::create(self::TWIG_TEMPLATE_DIR, $settings->getTwigSettings());
+            $twig = Twig::create(self::TWIG_TEMPLATE_DIR, $config->getTwigSettings());
 
             // Set default date format
             /** @var TwigCoreExtension $coreExtension */
             $coreExtension = $twig->getEnvironment()->getExtension(TwigCoreExtension::class);
-            $coreExtension->setDateFormat($settings->getDateFormat());
-            $coreExtension->setTimezone($settings->getTimezone());
+            $coreExtension->setDateFormat($config->getDateTimeFormat());
+            $coreExtension->setTimezone($config->getTimezone());
 
             // Add app information to globals
             $appInfo = $c->get(AppInfo::class);
@@ -71,9 +72,9 @@ class Dependencies
 
         // Database connection
         $container->set(self::DATABASE, function (ContainerInterface $c) {
-            /** @var Settings $settings */
-            $settings = $c->get(self::SETTINGS);
-            $dbSettings = $settings->getDatabaseSettings();
+            /** @var AppConfig $config */
+            $config = $c->get(self::CONFIG);
+            $dbSettings = $config->getDatabaseSettings();
 
             return new PDO(
                 "mysql:dbname={$dbSettings['dbname']};host={$dbSettings['host']};port={$dbSettings['port']}",
@@ -108,7 +109,7 @@ class Dependencies
         });
 
         // Helper classes
-        $container->set(SessionHelper::class, function (ContainerInterface $c) {
+        $container->set(SessionHelper::class, function () {
             return new SessionHelper();
         });
 
@@ -120,7 +121,7 @@ class Dependencies
             );
         });
 
-        $container->set(PasswordHelper::class, function (ContainerInterface $c) {
+        $container->set(PasswordHelper::class, function () {
             return new PasswordHelper();
         });
 
diff --git a/src/Middlewares.php b/src/Middlewares.php
index 375e481..f60987f 100644
--- a/src/Middlewares.php
+++ b/src/Middlewares.php
@@ -4,14 +4,15 @@ declare(strict_types=1);
 namespace MailAccountAdmin;
 
 use MailAccountAdmin\Auth\AuthMiddleware;
+use MailAccountAdmin\Config\AppConfig;
 use Slim\App;
 use Slim\Views\TwigMiddleware;
 
 class Middlewares
 {
-    public static function setMiddlewares(App $app, Settings $settings): void
+    public static function setMiddlewares(App $app, AppConfig $config): void
     {
-        $displayErrorDetails = $settings->isDebugMode();
+        $displayErrorDetails = $config->isDebugMode();
 
         $app->addErrorMiddleware($displayErrorDetails, true, true);
         $app->add(new AuthMiddleware());
diff --git a/src/Settings.php b/src/Settings.php
deleted file mode 100644
index 4d1b989..0000000
--- a/src/Settings.php
+++ /dev/null
@@ -1,49 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace MailAccountAdmin;
-
-class Settings
-{
-    public function getAppTitle(): string
-    {
-        return getenv('APP_TITLE') ?: 'MailAccountAdmin';
-    }
-
-    public function isDebugMode(): bool
-    {
-        return getenv('APP_DEBUG') === 'true';
-    }
-
-    public function getTimezone(): string
-    {
-        return 'Europe/Berlin';
-    }
-
-    public function getDateFormat(): string
-    {
-        // Default date format (https://www.php.net/manual/en/datetime.format.php)
-        // RFC 2822 formatted date (Thu, 21 Dec 2000 16:01:07 +0200)
-        return 'r';
-    }
-
-    public function getTwigSettings(): array
-    {
-        return [
-            'cache' => getenv('TWIG_CACHE_DIR') ?: false,
-            'debug' => $this->isDebugMode(),
-            'strict_variables' => getenv('TWIG_STRICT') === 'true',
-        ];
-    }
-
-    public function getDatabaseSettings(): array
-    {
-        return [
-            'host' => getenv('DB_HOST') ?: 'localhost',
-            'port' => getenv('DB_PORT') ?: 3306,
-            'dbname' => getenv('DB_DATABASE') ?: '',
-            'username' => getenv('DB_USER') ?: '',
-            'password' => getenv('DB_PASSWORD') ?: '',
-        ];
-    }
-}
diff --git a/src/VersionHelper.php b/src/VersionHelper.php
index 4fd370a..1223bce 100644
--- a/src/VersionHelper.php
+++ b/src/VersionHelper.php
@@ -3,16 +3,18 @@ declare(strict_types=1);
 
 namespace MailAccountAdmin;
 
+use MailAccountAdmin\Config\AppConfig;
+
 class VersionHelper
 {
     private string $version;
 
-    public function __construct()
+    public function __construct(AppConfig $config)
     {
         $version = $this->loadFromVersionFile();
         if (!empty($version)) {
             $this->version = $version;
-        } elseif ($this->inDevelopmentMode()) {
+        } elseif ($config->getAppEnvironment() === 'development') {
             $this->version = '[dev version]';
         } else {
             $this->version = '[undefined version]';
@@ -34,9 +36,4 @@ class VersionHelper
         }
         return null;
     }
-
-    private function inDevelopmentMode(): bool
-    {
-        return getenv('APP_ENV') === 'development';
-    }
 }