documentation

readme.md

@@ -54,4 +54,13 @@ docker run \
   $IMAGE
 ```
 
+## Usage in other containers
+
+Connect other containers to the mailer network:
+
+```
+docker network connect mailer-network name_of_other_container
+```
+
+Now you can use the name of the mailer container, here `mailer` as smarthost name in that other container.