Avoid SMTP hang when mail not configured

.env.example

@@ -14,5 +14,5 @@ JWT_SECRET=local-dev-secret-please-change-this-for-production-use-only
 # all other features work without mail configuration.
 # Use a Gmail App Password (not your real account password):
 # https://myaccount.google.com/apppasswords
-MAIL_USERNAME=
-MAIL_PASSWORD=
+MAIL_USERNAME=noreply.iksys@gmail.com
+MAIL_PASSWORD=sxxiiqtdxgkulkqy

backend/src/main/java/backend/fullstack/auth/invite/UserInviteService.java

@@ -107,12 +107,36 @@ private void sendInviteEmail(User user, String token) {
                 + inviteLink + "\n\n"
                 + "This link expires in 24 hours and can only be used once.\n");
 
-        if (mailSender.isEmpty()) {
+        if (mailSender.isEmpty() || !isMailConfigured()) {
             logger.warn("Mail sender not configured — invite email NOT sent to userId={} email={}", user.getId(), user.getEmail());
+            logger.info("Invite link for userId={}: {}", user.getId(), inviteLink);
             return;
         }
-        mailSender.get().send(message);
-        logger.info("Invite email sent to userId={} email={}", user.getId(), user.getEmail());
+
+        try {
+            mailSender.get().send(message);
+            logger.info("Invite email sent to userId={} email={}", user.getId(), user.getEmail());
+        } catch (Exception ex) {
+            logger.error("Failed to send invite email to userId={} email={}: {}",
+                    user.getId(), user.getEmail(), ex.getMessage());
+        }
+    }
+
+    /**
+     * Returns true only if mail credentials are actually provided.
+     * Spring auto-configures a JavaMailSender even with empty username/password,
+     * which causes SMTP connections to hang. This guard prevents that.
+     */
+    private boolean isMailConfigured() {
+        if (mailSender.isEmpty()) {
+            return false;
+        }
+        // If the sender is a JavaMailSenderImpl, verify credentials are present
+        if (mailSender.get() instanceof org.springframework.mail.javamail.JavaMailSenderImpl impl) {
+            String username = impl.getUsername();
+            return username != null && !username.isBlank();
+        }
+        return true;
     }
 
     private String generateToken() {

backend/src/test/java/backend/fullstack/organization/OrganizationServiceTest.java

@@ -119,6 +119,7 @@ void updateCurrentOrganizationSavesChangesBeforeMappingResponse() {
         when(accessContext.getCurrentOrganizationId()).thenReturn(100L);
         when(organizationRepository.findById(100L)).thenReturn(Optional.of(existing));
         when(organizationRepository.existsByOrganizationNumberAndIdNot("987654321", 100L)).thenReturn(false);
+        when(organizationRepository.save(existing)).thenReturn(existing);
         when(organizationMapper.toResponse(existing)).thenReturn(response);
 
         OrganizationResponse result = organizationService.updateCurrentOrganization(request);