Document it a bit more clear

Author: furstblumier

charts/docker-mailserver/values.yaml

@@ -296,12 +296,13 @@ deployment:
 service:
   ## What scope the service should be exposed in. One of:
   ## - LoadBalancer (to the world)
+  ## - NodePort (to the world, via high port on a node)
   ## - ClusterIP (to the cluster)
   type: "LoadBalancer"
   ## Manually overwrite the externalTrafficPolicy. One of:
   ## - Local
   ## - Cluster
-  ## Set it to "Local" when used with type "LoadBalancer" and set it to "Cluster" when used with type "ClusterIP",
+  ## Set it to "Local" when used with type "LoadBalancer" and set it to "Cluster" when used with type "ClusterIP" or "NodePort",
   ## unless you have a good reason not to.
   externalTrafficPolicy: "Local"
   ## If there is a port associated with a given service, expose it here.