diff --git a/smtprelay.ini b/smtprelay.ini
index cca560ed..a6adf2c4 100644
--- a/smtprelay.ini
+++ b/smtprelay.ini
@@ -34,6 +34,10 @@
 ; accepting mails from client.
 ;local_forcetls = false
 
+; Only use remotes where FROM EMail address in received
+; EMail matches remote_sender.
+;strict_sender = false
+
 ; Socket timeout for read operations
 ; Duration string as sequence of decimal numbers,
 ; each with optional fraction and a unit suffix.