fix: 解决邮件发送错误，但是前端显示已发送的问题

backend/src/main/java/com/openisle/service/ResendEmailSender.java

@@ -1,5 +1,6 @@
 package com.openisle.service;
 
+import com.openisle.exception.EmailSendException;
 import java.util.HashMap;
 import java.util.Map;
 import org.springframework.beans.factory.annotation.Value;
@@ -7,8 +8,9 @@ import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
-import org.springframework.scheduling.annotation.Async;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
 
 @Service
@@ -23,7 +25,6 @@ public class ResendEmailSender extends EmailSender {
   private final RestTemplate restTemplate = new RestTemplate();
 
   @Override
-  @Async("notificationExecutor")
   public void sendEmail(String to, String subject, String text) {
     String url = "https://api.resend.com/emails"; // hypothetical endpoint
 
@@ -38,6 +39,20 @@ public class ResendEmailSender extends EmailSender {
     body.put("from", "openisle <" + fromEmail + ">");
 
     HttpEntity<Map<String, String>> entity = new HttpEntity<>(body, headers);
-    restTemplate.exchange(url, HttpMethod.POST, entity, String.class);
+    try {
+      ResponseEntity<String> response = restTemplate.exchange(
+        url,
+        HttpMethod.POST,
+        entity,
+        String.class
+      );
+      if (!response.getStatusCode().is2xxSuccessful()) {
+        throw new EmailSendException(
+          "Email service returned status " + response.getStatusCodeValue()
+        );
+      }
+    } catch (RestClientException e) {
+      throw new EmailSendException("Failed to send email: " + e.getMessage(), e);
+    }
   }
 }