diff --git a/lib/features/mailbox_dashboard/presentation/model/search/search_email_filter.dart b/lib/features/mailbox_dashboard/presentation/model/search/search_email_filter.dart
index 121c0abda..5759e86a9 100644
--- a/lib/features/mailbox_dashboard/presentation/model/search/search_email_filter.dart
+++ b/lib/features/mailbox_dashboard/presentation/model/search/search_email_filter.dart
@@ -109,9 +109,6 @@ class SearchEmailFilter with EquatableMixin, OptionParamMixin {
       from: from.length == 1
         ? from.first
         : null,
-      notKeyword: notKeyword.length == 1
-        ? notKeyword.first
-        : null,
       hasKeyword: hasKeyword.length == 1
         ? hasKeyword.first
         : null,
@@ -127,7 +124,7 @@ class SearchEmailFilter with EquatableMixin, OptionParamMixin {
           Operator.OR,
           from.map((e) => EmailFilterCondition(from: e)).toSet(),
         ),
-      if (notKeyword.length > 1)
+      if (notKeyword.isNotEmpty)
         LogicFilterOperator(
           Operator.NOT,
           notKeyword.map((e) => EmailFilterCondition(text: e)).toSet(),
diff --git a/test/features/search/search_email_filter_test.dart b/test/features/search/search_email_filter_test.dart
index 06bfd1065..2f13df490 100644
--- a/test/features/search/search_email_filter_test.dart
+++ b/test/features/search/search_email_filter_test.dart
@@ -164,6 +164,26 @@ void main() {
         expect(logicOperator.operator, Operator.AND);
         expect(logicOperator.conditions.length, greaterThan(1));
       });
+
+      test('SHOULD wrap a simple EmailFilterCondition inside a NOT LogicFilterOperator when notKeyword is given', () {
+        // Arrange
+        final filter = SearchEmailFilter(
+          notKeyword: {'hello'},
+        );
+
+        // Act
+        final result = filter.mappingToEmailFilterCondition();
+
+        // Assert
+        expect(result, isA<LogicFilterOperator>());
+        final logicFilter = result as LogicFilterOperator;
+        expect(result.conditions.isNotEmpty, isTrue);
+        expect(logicFilter.operator, equals(Operator.NOT));
+
+        final emailCondition = result.conditions.first as EmailFilterCondition;
+        expect(emailCondition.text, 'hello');
+        expect(emailCondition.notKeyword, isNull);
+      });
     });
   });
 }