Update u_e-unbound-fwd.md

docs/u_e-unbound-fwd.md

@@ -1,19 +1,34 @@
-If you want or have to use an external DNS service, you can define it in `data/conf/unbound/unbound.conf`:
+If you want or have to use an external DNS service, you can either set a forwarder in Unbound or copy an override file to define external DNS servers:
+
+   !!! warning
+   Please do not use a public resolver like we did in the example above. Many - if not all - blacklist lookups will fail with public resolvers.
+   **Important**: Only DNSSEC validating DNS services will work.
+
+## Method A, Unbound
+
+Edit `data/conf/unbound/unbound.conf` and append the following parameters:
 
 ```
 forward-zone:
   name: "."
-  forward-addr: 8.8.8.8
-  forward-addr: 8.8.4.4
+  forward-addr: 8.8.8.8 # NO NOT USE PUBLIC DNS SERVERS - JUST AN EXAMPLE
+  forward-addr: 8.8.4.4 # NO NOT USE PUBLIC DNS SERVERS - JUST AN EXAMPLE
 ```
 
-Please do not use a public resolver like we did in the example above. Many - if not all - blacklist lookups will fail with public resolvers.
-
-**Important**: Only DNSSEC validating DNS services will work.
-
-Restart Unbound after changing its config file:
+Restart Unbound:
 
 ```
 docker-compose restart unbound-mailcow
 ```
 
+
+## Method B, Override file
+
+```
+cd /opt/mailcow-dockerized
+cp helper-scripts/docker-compose.override.yml.d/EXTERNAL_DNS/docker-compose.override.yml .
+```
+
+Edit `docker-compose.override.yml` and adjust the IP.
+
+Run `docker-compose down ; docker-compose up -d`.