diff --git a/lib/features/email/domain/state/calendar_event_reject_state.dart b/lib/features/email/domain/state/calendar_event_reject_state.dart
new file mode 100644
index 000000000..08929aec4
--- /dev/null
+++ b/lib/features/email/domain/state/calendar_event_reject_state.dart
@@ -0,0 +1,15 @@
+import 'package:jmap_dart_client/jmap/mail/calendar/reply/calendar_event_reject_response.dart';
+import 'package:tmail_ui_user/features/email/domain/state/calendar_event_reply_state.dart';
+
+class CalendarEventRejecting extends CalendarEventReplying {}
+
+class CalendarEventRejected extends CalendarEventReplySuccess {
+  final CalendarEventRejectResponse calendarEventRejectResponse;
+  
+  CalendarEventRejected(this.calendarEventRejectResponse)
+    : super(calendarEventRejectResponse);
+}
+
+class CalendarEventRejectFailure extends CalendarEventReplyFailure {
+  CalendarEventRejectFailure({super.exception});
+}
\ No newline at end of file
diff --git a/lib/features/email/domain/usecases/calendar_event_reject_interactor.dart b/lib/features/email/domain/usecases/calendar_event_reject_interactor.dart
new file mode 100644
index 000000000..433c2a75f
--- /dev/null
+++ b/lib/features/email/domain/usecases/calendar_event_reject_interactor.dart
@@ -0,0 +1,26 @@
+import 'package:core/presentation/state/failure.dart';
+import 'package:core/presentation/state/success.dart';
+import 'package:dartz/dartz.dart';
+import 'package:jmap_dart_client/jmap/account_id.dart';
+import 'package:jmap_dart_client/jmap/core/id.dart';
+import 'package:tmail_ui_user/features/email/domain/repository/calendar_event_repository.dart';
+import 'package:tmail_ui_user/features/email/domain/state/calendar_event_reject_state.dart';
+
+class RejectCalendarEventInteractor {
+  RejectCalendarEventInteractor(this._calendarEventRepository);
+
+  final CalendarEventRepository _calendarEventRepository;
+
+  Stream<Either<Failure, Success>> execute(
+    AccountId accountId,
+    Set<Id> blobIds
+  ) async* {
+    try {
+      yield Right(CalendarEventRejecting());
+      final result = await _calendarEventRepository.rejectEventInvitation(accountId, blobIds);
+      yield Right(CalendarEventRejected(result));
+    } catch (e) {
+      yield Left(CalendarEventRejectFailure(exception: e));
+    }
+  }
+}
\ No newline at end of file
diff --git a/test/features/email/domain/usecases/calendar_event_reject_interactor_test.dart b/test/features/email/domain/usecases/calendar_event_reject_interactor_test.dart
new file mode 100644
index 000000000..462d11412
--- /dev/null
+++ b/test/features/email/domain/usecases/calendar_event_reject_interactor_test.dart
@@ -0,0 +1,51 @@
+import 'package:dartz/dartz.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:jmap_dart_client/jmap/account_id.dart';
+import 'package:jmap_dart_client/jmap/core/id.dart';
+import 'package:jmap_dart_client/jmap/mail/calendar/properties/event_id.dart';
+import 'package:jmap_dart_client/jmap/mail/calendar/reply/calendar_event_reject_response.dart';
+import 'package:mockito/mockito.dart';
+import 'package:tmail_ui_user/features/email/domain/exceptions/calendar_event_exceptions.dart';
+import 'package:tmail_ui_user/features/email/domain/state/calendar_event_reject_state.dart';
+import 'package:tmail_ui_user/features/email/domain/usecases/calendar_event_reject_interactor.dart';
+
+import 'calendar_event_accept_interactor_test.mocks.dart';
+
+void main() {
+  final calendarEventRepository = MockCalendarEventRepository();
+  final rejectCalendarEventInteractor = RejectCalendarEventInteractor(calendarEventRepository);
+  final accountId = AccountId(Id('123'));
+  final blobId = Id('123321');
+
+  group('calendar event reject interactor test:', () {
+    test('should emit CalendarEventRejected when repo return data', () {
+      // arrange
+      final calendarEventRejectResponse = CalendarEventRejectResponse(
+        accountId,
+        null,
+        rejected: [EventId(blobId.value)]);
+      when(calendarEventRepository.rejectEventInvitation(any, any))
+        .thenAnswer((_) async => calendarEventRejectResponse);
+
+      // assert
+      expect(
+        rejectCalendarEventInteractor.execute(accountId, {blobId}),
+        emitsInOrder([
+          Right(CalendarEventRejecting()),
+          Right(CalendarEventRejected(calendarEventRejectResponse))]));
+    });
+
+    test('should emit CalendarEventRejectFailure when repo throw exception', () {
+      // arrange
+      final exception = NotRejectableCalendarEventException();
+      when(calendarEventRepository.rejectEventInvitation(any, any)).thenThrow(exception);
+
+      // assert
+      expect(
+        rejectCalendarEventInteractor.execute(accountId, {blobId}),
+        emitsInOrder([
+          Right(CalendarEventRejecting()),
+          Left(CalendarEventRejectFailure(exception: exception))]));
+    });
+  });
+}
\ No newline at end of file