diff --git a/README.md b/README.md
index 35d31a8..6b43ae4 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,10 @@
 # docker-postfix
 Simple postfix relay host for your Docker containers. Based on Alpine Linux.
 
+```
 ENV vars
 $HOSTNAME= Postfix myhostname
 $RELAYHOST= Host that relays your msgs
 $MYNETWORKS= allow domains from per Network ( default 127.0.0.0/8,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16 )
 $ALLOWED_SENDER_DOMAINS = domains sender domains
+```