diff --git a/lib/Data.php b/lib/Data.php
index fa856f26f..357c2d857 100644
--- a/lib/Data.php
+++ b/lib/Data.php
@@ -39,6 +39,38 @@ public function __construct(
 	) {
 	}
 
+	/**
+	 * Check if the event should be processed (not excluded and has valid target)
+	 *
+	 * @param IEvent $event
+	 * @return bool
+	 */
+	private function shouldSend(IEvent $event): bool {
+		return $event->getAffectedUser() !== '' && !$this->isExcludedAuthor($event);
+	}
+
+	/**
+	 * Check if the event's author is excluded from activity logging
+	 *
+	 * @param IEvent $event
+	 * @return bool
+	 */
+	private function isExcludedAuthor(IEvent $event): bool {
+		$excludedUsers = $this->config->getSystemValue('activity_log_exclude_users', []);
+		if (empty($excludedUsers)) {
+			return false;
+		}
+		$author = $event->getAuthor();
+		if ($author === '' || !isset($excludedUsers[$author])) {
+			return false;
+		}
+		$rule = $excludedUsers[$author];
+		if (is_array($rule)) {
+			return in_array($event->getType(), $rule, true);
+		}
+		return false;
+	}
+
 	/**
 	 * Send an event into the activity stream
 	 *
@@ -46,7 +78,7 @@ public function __construct(
 	 * @return int
 	 */
 	public function send(IEvent $event): int {
-		if ($event->getAffectedUser() === '') {
+		if (!$this->shouldSend($event)) {
 			return 0;
 		}
 
@@ -104,6 +136,10 @@ public function send(IEvent $event): int {
 	 * @throws Exception
 	 */
 	public function bulkSend(IEvent $event, array $affectedUsers): array {
+		if ($this->isExcludedAuthor($event)) {
+			return [];
+		}
+
 		$this->connection->beginTransaction();
 
 		$activityIds = [];
@@ -170,8 +206,7 @@ public function bulkSend(IEvent $event, array $affectedUsers): array {
 	 * @return bool
 	 */
 	public function storeMail(IEvent $event, int $latestSendTime): bool {
-		$affectedUser = $event->getAffectedUser();
-		if ($affectedUser === '') {
+		if (!$this->shouldSend($event)) {
 			return false;
 		}
 
@@ -195,7 +230,7 @@ public function storeMail(IEvent $event, int $latestSendTime): bool {
 			'amq_appid' => $event->getApp(),
 			'amq_subject' => $event->getSubject(),
 			'amq_subjectparams' => json_encode($event->getSubjectParameters()),
-			'amq_affecteduser' => $affectedUser,
+			'amq_affecteduser' => $event->getAffectedUser(),
 			'amq_timestamp' => $event->getTimestamp(),
 			'amq_type' => $event->getType(),
 			'amq_latest_send' => $latestSendTime,
diff --git a/tests/DataTest.php b/tests/DataTest.php
index 1ff577a49..a227ea194 100644
--- a/tests/DataTest.php
+++ b/tests/DataTest.php
@@ -347,6 +347,129 @@ public function testDeleteAffectedUserActivities(): void {
 		$this->deleteTestActivities();
 	}
 
+	public static function dataExcludedAuthor(): array {
+		return [
+			// author+type match → blocked
+			['alice', 'target', 'file_created', ['alice' => ['file_created']], false],
+			// type mismatch → allowed
+			['alice', 'target', 'file_created', ['alice' => ['file_deleted']], true],
+			// different user → allowed
+			['bob', 'target', 'file_created', ['alice' => ['file_created']], true],
+			// empty config → allowed
+			['alice', 'target', 'file_created', [], true],
+			// non-array rule → allowed
+			['alice', 'target', 'file_created', ['alice' => 'file_created'], true],
+		];
+	}
+
+	#[DataProvider('dataExcludedAuthor')]
+	public function testSendWithExcludedAuthor(string $author, string $affectedUser, string $type, array $excludedUsers, bool $expectedInsert): void {
+		$this->deleteTestActivities();
+
+		$this->config->method('getSystemValue')
+			->with('activity_log_exclude_users', [])
+			->willReturn($excludedUsers);
+
+		$event = $this->realActivityManager->generateEvent();
+		$event->setApp('test')
+			->setType($type)
+			->setAuthor($author)
+			->setAffectedUser($affectedUser)
+			->setSubject('subject');
+
+		$result = $this->data->send($event);
+		$this->assertSame($expectedInsert, $result !== 0);
+
+		$qb = $this->dbConnection->getQueryBuilder();
+		$row = $qb->select('user', 'affecteduser')
+			->from('activity')
+			->where($qb->expr()->eq('app', $qb->createNamedParameter('test')))
+			->orderBy('activity_id', 'DESC')
+			->executeQuery()
+			->fetch();
+
+		if ($expectedInsert) {
+			$this->assertEquals(['user' => $author, 'affecteduser' => $affectedUser], $row);
+		} else {
+			$this->assertFalse($row);
+		}
+
+		$this->deleteTestActivities();
+	}
+
+	#[DataProvider('dataExcludedAuthor')]
+	public function testStoreMailWithExcludedAuthor(string $author, string $affectedUser, string $type, array $excludedUsers, bool $expectedInsert): void {
+		$this->deleteTestMails();
+
+		$this->config->method('getSystemValue')
+			->with('activity_log_exclude_users', [])
+			->willReturn($excludedUsers);
+
+		$time = time();
+		$event = $this->realActivityManager->generateEvent();
+		$event->setApp('test')
+			->setType($type)
+			->setAuthor($author)
+			->setAffectedUser($affectedUser)
+			->setSubject('subject')
+			->setTimestamp($time);
+
+		$this->assertSame($expectedInsert, $this->data->storeMail($event, $time + 10));
+
+		$qb = $this->dbConnection->getQueryBuilder();
+		$row = $qb->select('amq_latest_send', 'amq_affecteduser')
+			->from('activity_mq')
+			->where($qb->expr()->eq('amq_appid', $qb->createNamedParameter('test')))
+			->orderBy('mail_id', 'DESC')
+			->executeQuery()
+			->fetch();
+
+		if ($expectedInsert) {
+			$this->assertEquals(['amq_latest_send' => $time + 10, 'amq_affecteduser' => $affectedUser], $row);
+		} else {
+			$this->assertFalse($row);
+		}
+
+		$this->deleteTestMails();
+	}
+
+	#[DataProvider('dataExcludedAuthor')]
+	public function testBulkSendWithExcludedAuthor(string $author, string $_affectedUser, string $type, array $excludedUsers, bool $expectedInsert): void {
+		$this->deleteTestActivities();
+
+		$this->config->method('getSystemValue')
+			->with('activity_log_exclude_users', [])
+			->willReturn($excludedUsers);
+
+		$event = $this->realActivityManager->generateEvent();
+		$event->setApp('test')
+			->setType($type)
+			->setAuthor($author)
+			->setSubject('subject')
+			->setTimestamp(time());
+
+		$bulkUsers = ['user1', 'user2'];
+		$result = $this->data->bulkSend($event, $bulkUsers);
+
+		if ($expectedInsert) {
+			$this->assertCount(2, $result);
+			$this->assertEqualsCanonicalizing($bulkUsers, array_values($result));
+		} else {
+			$this->assertEmpty($result);
+		}
+
+		$qb = $this->dbConnection->getQueryBuilder();
+		$count = (int)$qb->select($qb->func()->count('activity_id', 'count'))
+			->from('activity')
+			->where($qb->expr()->eq('app', $qb->createNamedParameter('test')))
+			->executeQuery()
+			->fetch()['count'];
+
+		$this->assertSame($expectedInsert ? 2 : 0, $count);
+
+		$this->deleteTestActivities();
+	}
+
 	/**
 	 * Delete all testing activities
 	 */