diff --git a/cs25-batch/src/main/java/com/example/cs25batch/aop/MailLogAspect.java b/cs25-batch/src/main/java/com/example/cs25batch/aop/MailLogAspect.java
index 2b50daec..89d00a0b 100644
--- a/cs25-batch/src/main/java/com/example/cs25batch/aop/MailLogAspect.java
+++ b/cs25-batch/src/main/java/com/example/cs25batch/aop/MailLogAspect.java
@@ -48,7 +48,7 @@ public Object logMailSend(ProceedingJoinPoint joinPoint) throws Throwable {
             caused = e.getMessage();
             throw new CustomMailException(MailExceptionCode.EMAIL_SEND_FAILED_ERROR);
         } finally {
-            MailLog log = MailLog.builder()
+            MailLog mailLog = MailLog.builder()
                 .subscription(subscription)
                 .quiz(quiz)
                 .sendDate(LocalDateTime.now())
@@ -56,10 +56,11 @@ public Object logMailSend(ProceedingJoinPoint joinPoint) throws Throwable {
                 .caused(caused)
                 .build();
 
-            mailLogRepository.save(log);
+            mailLogRepository.save(mailLog);
             mailLogRepository.flush();
 
             if (status == MailStatus.FAILED) {
+                log.info("메일 발송 실패 : subscriptionId - {}, cause - {}", subscription.getId(), caused);
                 Map<String, String> retryMessage = Map.of(
                     "email", subscription.getEmail(),
                     "subscriptionId", subscription.getId().toString(),
diff --git a/cs25-entity/src/main/java/com/example/cs25entity/domain/mail/repository/MailLogRepository.java b/cs25-entity/src/main/java/com/example/cs25entity/domain/mail/repository/MailLogRepository.java
index a9184764..3431079d 100644
--- a/cs25-entity/src/main/java/com/example/cs25entity/domain/mail/repository/MailLogRepository.java
+++ b/cs25-entity/src/main/java/com/example/cs25entity/domain/mail/repository/MailLogRepository.java
@@ -7,6 +7,8 @@
 import java.util.Optional;
 import java.util.Set;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 @Repository
@@ -23,5 +25,11 @@ default MailLog findByIdOrElseThrow(Long id) {
 
     void deleteAllByIdIn(Collection<Long> ids);
 
-    Set<Long> findDistinctQuiz_IdBySubscription_Id(Long subscriptionId);
+    @Query("""
+          select distinct ml.quiz.id
+          from MailLog ml
+          where ml.subscription.id = :subscriptionId
+            and ml.status = com.example.cs25entity.domain.mail.enums.MailStatus.SENT
+        """)
+    Set<Long> findDistinctQuiz_IdBySubscription_Id(@Param("subscriptionId") Long subscriptionId);
 }
diff --git a/cs25-service/src/main/java/com/example/cs25service/domain/ai/service/AiFeedbackStreamProcessor.java b/cs25-service/src/main/java/com/example/cs25service/domain/ai/service/AiFeedbackStreamProcessor.java
index d9eee6cc..c159fb6d 100644
--- a/cs25-service/src/main/java/com/example/cs25service/domain/ai/service/AiFeedbackStreamProcessor.java
+++ b/cs25-service/src/main/java/com/example/cs25service/domain/ai/service/AiFeedbackStreamProcessor.java
@@ -4,6 +4,8 @@
 import com.example.cs25entity.domain.user.repository.UserRepository;
 import com.example.cs25entity.domain.userQuizAnswer.repository.UserQuizAnswerRepository;
 import com.example.cs25service.domain.ai.client.AiChatClient;
+//import com.example.cs25service.domain.ai.exception.AiException;
+//import com.example.cs25service.domain.ai.exception.AiExceptionCode;
 import com.example.cs25service.domain.ai.prompt.AiPromptProvider;
 import com.fasterxml.jackson.databind.JsonNode;
 import java.io.IOException;
@@ -89,9 +91,9 @@ public void stream(Long answerId, SseEmitter emitter) {
                         send(emitter, "[종료]");
 
                         String feedback = fullFeedbackBuffer.toString();
-                        if (feedback == null || feedback.isEmpty()) {
-                            throw new AiException(AiExceptionCode.INTERNAL_SERVER_ERROR);
-                        }
+//                        if (feedback == null || feedback.isEmpty()) {
+//                            throw new AiException(AiExceptionCode.INTERNAL_SERVER_ERROR);
+//                        }
 
                         boolean isCorrect = isCorrect(feedback);