diff --git a/Classes/Domain/Service/Email/SendSummaryService.php b/Classes/Domain/Service/Email/SendSummaryService.php
index c8ec6619..023d3871 100644
--- a/Classes/Domain/Service/Email/SendSummaryService.php
+++ b/Classes/Domain/Service/Email/SendSummaryService.php
@@ -22,9 +22,6 @@ class SendSummaryService
     protected array $visitors;
     protected ?ConfigurationService $configurationService = null;
 
-    /**
-     * @param array $visitors
-     */
     public function __construct(array $visitors)
     {
         $this->visitors = $visitors;
@@ -32,8 +29,6 @@ public function __construct(array $visitors)
     }
 
     /**
-     * @param array $emails
-     * @return bool
      * @throws ConfigurationException
      * @throws EmailValidationException
      * @throws InvalidConfigurationTypeException
@@ -53,34 +48,49 @@ public function send(array $emails): bool
     }
 
     /**
-     * @return array
+     * @throws ConfigurationException
      * @throws InvalidConfigurationTypeException
      */
     protected function getSender(): array
     {
-        $configuration = $this->configurationService->getTypoScriptSettingsByPath('commandControllers.summaryMail');
+        $configuration = $this->getSummaryMailConfiguration();
         return [$configuration['fromEmail'] => $configuration['fromName']];
     }
 
     /**
-     * @return string
+     * @throws ConfigurationException
      * @throws InvalidConfigurationTypeException
      */
     protected function getSubject(): string
     {
-        return $this->configurationService->getTypoScriptSettingsByPath('commandControllers.summaryMail.subject');
+        return $this->getSummaryMailConfiguration()['subject'] ?? '';
     }
 
     /**
-     * @param array $assignment
-     * @return string
+     * @throws ConfigurationException
+     * @throws InvalidConfigurationTypeException
+     */
+    protected function getSummaryMailConfiguration(): array
+    {
+        $configuration = $this->configurationService->getTypoScriptSettingsByPath('commandControllers.summaryMail');
+        if (is_array($configuration) === false) {
+            throw new ConfigurationException(
+                'TypoScript setting plugin.tx_lux_fe.settings.commandControllers.summaryMail could not be '
+                . 'resolved. Please add the static TypoScript of EXT:lux to the TypoScript template of the '
+                . 'site that is used by this command.',
+                1789652586
+            );
+        }
+        return $configuration;
+    }
+
+    /**
+     * @throws ConfigurationException
      * @throws InvalidConfigurationTypeException
      */
     protected function getMailTemplate(array $assignment = []): string
     {
-        $mailTemplatePath = $this->configurationService->getTypoScriptSettingsByPath(
-            'commandControllers.summaryMail.mailTemplate'
-        );
+        $mailTemplatePath = $this->getSummaryMailConfiguration()['mailTemplate'] ?? '';
         $view = GeneralUtility::makeInstance(ViewFactoryInterface::class)->create(new ViewFactoryData(
             templatePathAndFilename: GeneralUtility::getFileAbsFileName($mailTemplatePath),
         ));
@@ -89,12 +99,10 @@ protected function getMailTemplate(array $assignment = []): string
     }
 
     /**
-     * @param array $emails
-     * @return void
      * @throws EmailValidationException
      * @throws ConfigurationException
      */
-    protected function checkProperties(array $emails)
+    protected function checkProperties(array $emails): void
     {
         if ($emails === []) {
             throw new ConfigurationException('No emails to send given', 1524299754);
diff --git a/Tests/Unit/Domain/Service/Email/SendSummaryServiceTest.php b/Tests/Unit/Domain/Service/Email/SendSummaryServiceTest.php
new file mode 100644
index 00000000..751b0fe7
--- /dev/null
+++ b/Tests/Unit/Domain/Service/Email/SendSummaryServiceTest.php
@@ -0,0 +1,205 @@
+<?php
+
+declare(strict_types=1);
+
+namespace In2code\Lux\Tests\Unit\Domain\Service\Email;
+
+use In2code\Lux\Domain\Model\Visitor;
+use In2code\Lux\Domain\Service\ConfigurationService;
+use In2code\Lux\Domain\Service\Email\SendSummaryService;
+use In2code\Lux\Exception\ConfigurationException;
+use In2code\Lux\Exception\EmailValidationException;
+use In2code\Lux\Tests\Helper\TestingHelper;
+use In2code\Lux\Tests\Unit\Fixtures\Domain\Service\Email\SendSummaryServiceFixture;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\CoversMethod;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Test;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\TestingFramework\Core\Unit\UnitTestCase;
+
+#[CoversClass(SendSummaryService::class)]
+#[CoversMethod(SendSummaryService::class, '__construct')]
+#[CoversMethod(SendSummaryService::class, 'getSummaryMailConfiguration')]
+#[CoversMethod(SendSummaryService::class, 'getSender')]
+#[CoversMethod(SendSummaryService::class, 'getSubject')]
+#[CoversMethod(SendSummaryService::class, 'getMailTemplate')]
+#[CoversMethod(SendSummaryService::class, 'checkProperties')]
+class SendSummaryServiceTest extends UnitTestCase
+{
+    protected const MISSING_CONFIGURATION_EXCEPTION_CODE = 1789652586;
+
+    protected const VALID_CONFIGURATION = [
+        'fromEmail' => 'sender@domain.org',
+        'fromName' => 'Sender Name',
+        'subject' => 'Your lead summary',
+        'mailTemplate' => 'EXT:lux/Resources/Private/Templates/Mail/SummaryMail.html',
+    ];
+
+    protected bool $resetSingletonInstances = true;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+        TestingHelper::setDefaultConstants();
+    }
+
+    #[Test]
+    public function testGetSummaryMailConfigurationReturnsConfiguration(): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION);
+        self::assertSame(self::VALID_CONFIGURATION, $service->getSummaryMailConfigurationPublic());
+    }
+
+    #[Test]
+    public function testGetSenderReturnsEmailAndName(): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION);
+        self::assertSame(['sender@domain.org' => 'Sender Name'], $service->getSenderPublic());
+    }
+
+    #[Test]
+    public function testGetSubjectReturnsSubject(): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION);
+        self::assertSame('Your lead summary', $service->getSubjectPublic());
+    }
+
+    #[Test]
+    public function testGetSubjectReturnsEmptyStringOnMissingSubject(): void
+    {
+        $configuration = self::VALID_CONFIGURATION;
+        unset($configuration['subject']);
+        $service = $this->getServiceFixture($configuration);
+        self::assertSame('', $service->getSubjectPublic());
+    }
+
+    public static function missingConfigurationDataProvider(): array
+    {
+        return [
+            'empty string from unresolvable typoscript path' => [''],
+            'string instead of array' => ['summaryMail'],
+            'null' => [null],
+            'integer' => [0],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('missingConfigurationDataProvider')]
+    public function testGetSummaryMailConfigurationThrowsExceptionOnMissingConfiguration(
+        mixed $configuration
+    ): void {
+        $service = $this->getServiceFixture($configuration);
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionCode(self::MISSING_CONFIGURATION_EXCEPTION_CODE);
+        $service->getSummaryMailConfigurationPublic();
+    }
+
+    #[Test]
+    public function testGetSummaryMailConfigurationExceptionMessageNamesTypoScriptPath(): void
+    {
+        $service = $this->getServiceFixture('');
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionMessageMatches('~plugin\.tx_lux_fe\.settings\.commandControllers\.summaryMail~');
+        $service->getSummaryMailConfigurationPublic();
+    }
+
+    #[Test]
+    public function testGetSenderThrowsExceptionOnMissingConfiguration(): void
+    {
+        $service = $this->getServiceFixture('');
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionCode(self::MISSING_CONFIGURATION_EXCEPTION_CODE);
+        $service->getSenderPublic();
+    }
+
+    #[Test]
+    public function testGetSubjectThrowsExceptionOnMissingConfiguration(): void
+    {
+        $service = $this->getServiceFixture('');
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionCode(self::MISSING_CONFIGURATION_EXCEPTION_CODE);
+        $service->getSubjectPublic();
+    }
+
+    #[Test]
+    public function testGetMailTemplateThrowsExceptionOnMissingConfiguration(): void
+    {
+        $service = $this->getServiceFixture('');
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionCode(self::MISSING_CONFIGURATION_EXCEPTION_CODE);
+        $service->getMailTemplatePublic();
+    }
+
+    #[Test]
+    public function testConfigurationIsAlwaysResolvedFromTheSameTypoScriptPath(): void
+    {
+        $configurationService = $this->createMock(ConfigurationService::class);
+        $configurationService
+            ->expects(self::atLeastOnce())
+            ->method('getTypoScriptSettingsByPath')
+            ->with('commandControllers.summaryMail')
+            ->willReturn(self::VALID_CONFIGURATION);
+        GeneralUtility::setSingletonInstance(ConfigurationService::class, $configurationService);
+
+        $service = new SendSummaryServiceFixture([new Visitor()]);
+        $service->getSenderPublic();
+        $service->getSubjectPublic();
+    }
+
+    #[Test]
+    public function testCheckPropertiesThrowsExceptionOnEmptyEmails(): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION);
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionCode(1524299754);
+        $service->checkPropertiesPublic([]);
+    }
+
+    public static function invalidEmailDataProvider(): array
+    {
+        return [
+            'no email at all' => ['receiver'],
+            'missing domain' => ['receiver@'],
+            'missing local part' => ['@domain.org'],
+            'whitespace' => ['receiver @domain.org'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('invalidEmailDataProvider')]
+    public function testCheckPropertiesThrowsExceptionOnInvalidEmail(string $email): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION);
+        $this->expectException(EmailValidationException::class);
+        $this->expectExceptionCode(1524299869);
+        $service->checkPropertiesPublic([$email]);
+    }
+
+    #[Test]
+    public function testCheckPropertiesThrowsExceptionOnMissingVisitors(): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION, []);
+        $this->expectException(ConfigurationException::class);
+        $this->expectExceptionCode(1524300114);
+        $service->checkPropertiesPublic(['receiver@domain.org']);
+    }
+
+    #[Test]
+    public function testCheckPropertiesPassesWithValidProperties(): void
+    {
+        $service = $this->getServiceFixture(self::VALID_CONFIGURATION);
+        $this->expectNotToPerformAssertions();
+        $service->checkPropertiesPublic(['receiver@domain.org', 'receiver2@domain.org']);
+    }
+
+    protected function getServiceFixture(mixed $configuration, ?array $visitors = null): SendSummaryServiceFixture
+    {
+        $configurationService = self::createStub(ConfigurationService::class);
+        $configurationService
+            ->method('getTypoScriptSettingsByPath')
+            ->willReturn($configuration);
+        GeneralUtility::setSingletonInstance(ConfigurationService::class, $configurationService);
+        return new SendSummaryServiceFixture($visitors ?? [new Visitor()]);
+    }
+}
diff --git a/Tests/Unit/Fixtures/Domain/Service/Email/SendSummaryServiceFixture.php b/Tests/Unit/Fixtures/Domain/Service/Email/SendSummaryServiceFixture.php
new file mode 100644
index 00000000..5cdbb60d
--- /dev/null
+++ b/Tests/Unit/Fixtures/Domain/Service/Email/SendSummaryServiceFixture.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace In2code\Lux\Tests\Unit\Fixtures\Domain\Service\Email;
+
+use In2code\Lux\Domain\Service\Email\SendSummaryService;
+use In2code\Lux\Exception\ConfigurationException;
+use In2code\Lux\Exception\EmailValidationException;
+use TYPO3\CMS\Extbase\Configuration\Exception\InvalidConfigurationTypeException;
+
+class SendSummaryServiceFixture extends SendSummaryService
+{
+    /**
+     * @throws ConfigurationException
+     * @throws InvalidConfigurationTypeException
+     */
+    public function getSummaryMailConfigurationPublic(): array
+    {
+        return $this->getSummaryMailConfiguration();
+    }
+
+    /**
+     * @throws ConfigurationException
+     * @throws InvalidConfigurationTypeException
+     */
+    public function getSenderPublic(): array
+    {
+        return $this->getSender();
+    }
+
+    /**
+     * @throws ConfigurationException
+     * @throws InvalidConfigurationTypeException
+     */
+    public function getSubjectPublic(): string
+    {
+        return $this->getSubject();
+    }
+
+    /**
+     * @throws ConfigurationException
+     * @throws InvalidConfigurationTypeException
+     */
+    public function getMailTemplatePublic(array $assignment = []): string
+    {
+        return $this->getMailTemplate($assignment);
+    }
+
+    /**
+     * @throws ConfigurationException
+     * @throws EmailValidationException
+     */
+    public function checkPropertiesPublic(array $emails): void
+    {
+        $this->checkProperties($emails);
+    }
+}