diff --git a/server/lib/classes/monitor_tools.inc.php b/server/lib/classes/monitor_tools.inc.php
index 8b3ea99f8e5accf8adbd685df64f6ecf6859bb6f..45a56780849bce2a9d392064f7c900e19f08791f 100644
--- a/server/lib/classes/monitor_tools.inc.php
+++ b/server/lib/classes/monitor_tools.inc.php
@@ -250,7 +250,9 @@ class monitor_tools {
 				$filename = $mb['maildir'].'/.quotausage';
 				if(file_exists($filename) && !is_link($filename)) {
 					$quotafile = file($filename);
-					$data[$email]['used'] = trim($quotafile['1']);
+					preg_match('/storage.*?([0-9]+)/s', implode('',$quotafile), $storage_value);
+					$data[$email]['used'] = $storage_value[1];
+					$app->log("Mail storage $email: " . $storage_value[1], LOGLEVEL_DEBUG);
 					unset($quotafile);
 				} else {
 					exec('du -s '.escapeshellcmd($mb['maildir']), $out);