diff --git a/README.md b/README.md
index c78565f..7c4e980 100644
--- a/README.md
+++ b/README.md
@@ -64,6 +64,7 @@ dockerfiles
 - [x] node-red :+1:
 - [x] node-red-arm :+1:
 - [x] nullmailer
+- [x] nullmailer-arm
 - [x] obfsproxy
 - [x] opencart
 - [x] openvpn :+1:
diff --git a/nullmailer/README.md b/nullmailer/README.md
index 552cf63..943863b 100644
--- a/nullmailer/README.md
+++ b/nullmailer/README.md
@@ -36,9 +36,9 @@ nullmailer:
 $ cd ~/fig/nullmailer
 $ docker-compose up -d
 
-# send test email
-$ alias sendmail='docker exec -i nullmailer sendmail'
-$ echo -e 'Subject: hello\r\n\r\nworld' | sendmail username@gmail.com
+# send email (from gmail to yahoo)
+$ alias sendmail='docker exec -i nullmailer sendmail -f username@gmail.com'
+$ echo -e 'Subject: hello\r\n\r\nworld' | sendmail username@yahoo.com
 ```
 
 [1]: http://untroubled.org/nullmailer/