diff --git a/server/lib/classes/monitor_tools.inc.php b/server/lib/classes/monitor_tools.inc.php
index a44324528b0d1136de566060ec95bdc6f8ebae95..dbe702d0dd2473a898c3b11602a23d21c788a071 100644
--- a/server/lib/classes/monitor_tools.inc.php
+++ b/server/lib/classes/monitor_tools.inc.php
@@ -865,6 +865,7 @@ class monitor_tools {
 
 		//* Replace placeholders
 		$mailHeaders = strtr($mailHeaders, $placeholders);
+		$mailFrom = strtr($mailFrom, $placeholders);
 		$mailSubject = strtr($mailSubject, $placeholders);
 		$mailBody = strtr($mailBody, $placeholders);
 
@@ -872,11 +873,6 @@ class monitor_tools {
 			$app->functions->mail($recipients[$r], $mailSubject, $mailBody, $mailFrom);
 		}
 
-		unset($mailSubject);
-		unset($mailHeaders);
-		unset($mailBody);
-		unset($lines);
-
 		return true;
 	}