diff --git a/postfix.cf.tmpl b/postfix.cf.tmpl
index 5ba7305..86b1153 100644
--- a/postfix.cf.tmpl
+++ b/postfix.cf.tmpl
@@ -3,6 +3,7 @@
 # https://github.com/Mailu/Mailu/blob/master/core/postfix/conf/main.cf
 
 # Please note, this config assumes "recipient_delimiter = +" in the main.cf
+# and transport_maps/relay_domains preserve the overriden postfix.cf config values
 
 unknown_local_recipient_reject_code = 550
 owner_request_special = no