diff --git a/apps/base/stalwart/services.yaml b/apps/base/stalwart/services.yaml
index a1e90f7..2801283 100644
--- a/apps/base/stalwart/services.yaml
+++ b/apps/base/stalwart/services.yaml
@@ -30,6 +30,7 @@ metadata:
   namespace: stalwart
   annotations:
     external-dns.alpha.kubernetes.io/hostname: mail.main.unkin.net
+    purelb.io/service-group: dmz
 spec:
   type: LoadBalancer
   externalTrafficPolicy: Local