diff --git a/README.md b/README.md
index 050d23b4..a2728bd3 100644
--- a/README.md
+++ b/README.md
@@ -226,7 +226,7 @@ This should "deliver" a new message to the INBOX of _username@example.com_ by us
 
 ## Outbound SMTP
 
-Use [ZoneMTA](https://github.com/zone-eu/zone-mta) with the [ZoneMTA-WildDuck](https://github.com/nodemailer/zonemta-wildduck) plugin. This gives you an outbound SMTP server that uses Wild Duck accounts for authentication.
+Use [ZoneMTA](https://github.com/zone-eu/zone-mta) with the [ZoneMTA-WildDuck](https://github.com/nodemailer/zonemta-wildduck) plugin. This gives you an outbound SMTP server that uses Wild Duck accounts for authentication. The plugin authenticates user credentials and also rewrites headers if needed (if the header From: address does not match user address or aliases then it is rewritten). Additionally a copy of the sent message is uploaded to the Sent Mail folder.
 
 ## Inbound SMTP