diff --git a/include/config.inc.example b/include/config.inc.example
index 611dbca56..d0deec652 100644
--- a/include/config.inc.example
+++ b/include/config.inc.example
@@ -100,4 +100,4 @@ define ("DEBUGNOALYSS",0);
 // define ("NOALYSS_URL","https://demo.noalyss.eu");
 // For POSTFIX, when sending email from NOALYSS via sendmail an extra parameter is needed
 // for the Return-Path, the FROM will be replaced by the Sendmail_Core->from value
-//define("MAIL_EXTRA_PARAM","-f FROM")
+//define("MAIL_EXTRA_PARAM","-f [FROM]")
diff --git a/include/constant.php b/include/constant.php
index 8b942dc7c..00cf4ddc5 100644
--- a/include/constant.php
+++ b/include/constant.php
@@ -453,7 +453,7 @@ function noalyss_class_autoloader($class)
 
 }
 if ( ! defined("MAIL_EXTRA_PARAM")) {
-    define("MAIL_EXTRA_PARAM","-f FROM");
+    define("MAIL_EXTRA_PARAM","-f [FROM]");
 }
 spl_autoload_register('\noalyss_class_autoloader', true);
 
diff --git a/include/lib/config_file.php b/include/lib/config_file.php
index bd36d0066..1411ba687 100644
--- a/include/lib/config_file.php
+++ b/include/lib/config_file.php
@@ -310,8 +310,8 @@ EOF;
 // $a 
 // $a
 // For POSTFIX, when sending email from NOALYSS via sendmail an extra parameter is needed $a
-// for the Return-Path, the FROM will be replaced by the email of the sender (Sendmail_Core->from value)$a
-//define("MAIL_EXTRA_PARAM","-f FROM") $a
+// for the Return-Path, the [FROM] will be replaced by the email of the sender (Sendmail_Core->from value)$a
+//define("MAIL_EXTRA_PARAM","-f [FROM]") $a
 EOF;    
 }
 /*!
diff --git a/include/lib/sendmail_core.class.php b/include/lib/sendmail_core.class.php
index c8cc79c4d..2768119de 100644
--- a/include/lib/sendmail_core.class.php
+++ b/include/lib/sendmail_core.class.php
@@ -261,7 +261,7 @@ eof;
         if ( empty ($this->afile) ) $this->content.=$eol;
 
         $this->content .= "--" . $separator . "--";
-        $this->supplemental_param= str_replace("FROM", $this->from, $this->supplemental_param);
+        $this->supplemental_param= str_replace("[FROM]", $this->from, $this->supplemental_param);
     }
 
     /**