diff --git a/HowtoPostfix.md b/HowtoPostfix.md
index 70fa7d6e..bc131927 100644
--- a/HowtoPostfix.md
+++ b/HowtoPostfix.md
@@ -59,6 +59,7 @@ mailbox_size_limit = 0
 recipient_delimiter = +
 inet_interfaces = all
 inet_protocols = ipv4
+disable_vrfy_command = yes
 ~~~
 
 ### Configuration minimale pour serveur web