fix(MailQueueHandler): check enable_email toggle before sending queued emails

The admin Enable notification emails toggle was only checked when queuing
new emails. The sendEmails() background job had no knowledge of it and
would send all queued entries regardless.

Adds an early-return guard using IAppConfig::getValueString() at the top
of sendEmails(), consistent with the checks in UserSettings. The queue is
left intact so pending notifications can be delivered if the admin
re-enables emails.

AI-Assisted-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Anna Larch <anna@nextcloud.com>

Author: miaulalala

lib/AppInfo/Application.php

@@ -31,6 +31,7 @@
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
 use OCP\DB\Events\AddMissingIndicesEvent;
+use OCP\IAppConfig;
 use OCP\IConfig;
 use OCP\IDateTimeFormatter;
 use OCP\IDBConnection;
@@ -117,6 +118,7 @@ public function register(IRegistrationContext $context): void {
 				$c->get(IFactory::class),
 				$c->get(IManager::class),
 				$c->get(IValidator::class),
+				$c->get(IAppConfig::class),
 				$c->get(IConfig::class),
 				$c->get(LoggerInterface::class),
 				$c->get(Data::class),

lib/MailQueueHandler.php

@@ -11,6 +11,7 @@
 use OCP\Activity\IManager;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\Defaults;
+use OCP\IAppConfig;
 use OCP\IConfig;
 use OCP\IDateTimeFormatter;
 use OCP\IDBConnection;
@@ -51,6 +52,7 @@ public function __construct(
 		protected IFactory $lFactory,
 		protected IManager $activityManager,
 		protected IValidator $richObjectValidator,
+		protected IAppConfig $appConfig,
 		protected IConfig $config,
 		protected LoggerInterface $logger,
 		protected Data $data,
@@ -70,6 +72,10 @@ public function __construct(
 	 * @return int Number of users we sent an email to
 	 */
 	public function sendEmails(int $limit, int $sendTime, bool $forceSending = false, ?int $restrictEmails = null): int {
+		if ($this->appConfig->getValueString('activity', 'enable_email', 'yes') === 'no') {
+			return 0;
+		}
+
 		// Get all users which should receive an email
 		$affectedUsers = $this->getAffectedUsers($limit, $sendTime, $forceSending, $restrictEmails);
 		if (empty($affectedUsers)) {

tests/MailQueueHandlerTest.php

@@ -34,6 +34,7 @@
 use OCA\Activity\UserSettings;
 use OCP\Activity\IEvent;
 use OCP\Activity\IManager;
+use OCP\IAppConfig;
 use OCP\IConfig;
 use OCP\IDateTimeFormatter;
 use OCP\IDBConnection;
@@ -65,6 +66,7 @@ class MailQueueHandlerTest extends TestCase {
 	protected IFactory&MockObject $lFactory;
 	protected IManager&MockObject $activityManager;
 	protected IValidator&MockObject $richObjectValidator;
+	protected IAppConfig&MockObject $appConfig;
 	protected IConfig&MockObject $config;
 	protected MockObject&LoggerInterface $logger;
 
@@ -81,6 +83,7 @@ protected function setUp(): void {
 		$app = self::getUniqueID('MailQueueHandlerTest', 10);
 		$this->userManager = $this->createMock(IUserManager::class);
 		$this->lFactory = $this->createMock(IFactory::class);
+		$this->appConfig = $this->createMock(IAppConfig::class);
 		$this->config = $this->createMock(IConfig::class);
 		$this->logger = $this->createMock(LoggerInterface::class);
 		$this->dateTimeFormatter = $this->createMock(IDateTimeFormatter::class);
@@ -141,6 +144,7 @@ protected function setUp(): void {
 			$this->lFactory,
 			$this->activityManager,
 			$this->richObjectValidator,
+			$this->appConfig,
 			$this->config,
 			$this->logger,
 			$this->data,
@@ -370,6 +374,27 @@ public function testSendEmailsDeletesQueueOnSendReturnFalse(): void {
 		}
 	}
 
+	public function testSendEmailsSkipsWhenAdminEmailDisabled(): void {
+		$maxTime = 200;
+
+		$this->appConfig->method('getValueString')
+			->with('activity', 'enable_email', 'yes')
+			->willReturn('no');
+
+		$this->mailer->expects($this->never())
+			->method('send');
+
+		$result = $this->mailQueueHandler->sendEmails(3, $maxTime);
+
+		$this->assertSame(0, $result);
+
+		// Queue must be untouched so emails can be sent if admin re-enables the toggle
+		foreach (['user1', 'user2', 'user3'] as $user) {
+			[$data,] = self::invokePrivate($this->mailQueueHandler, 'getItemsForUser', [$user, $maxTime]);
+			$this->assertNotEmpty($data, "Queue entries for $user must survive when email is globally disabled");
+		}
+	}
+
 	/**
 	 * @param array $users
 	 * @param int $maxTime