Merge branch 'stable-3.1' of git.ispconfig.org:ispconfig/ispconfig3 into stable-3.1

interface/lib/plugins/mail_user_filter_plugin.inc.php

@@ -177,7 +177,7 @@ class mail_user_filter_plugin {
 				} elseif ($page_form->dataRecord["op"] == 'is') {
 					$content .= "^".$searchterm."$";
 				} elseif ($page_form->dataRecord["op"] == 'begins') {
-					$content .= " ".$searchterm."";
+					$content .= "^".$searchterm."";
 				} elseif ($page_form->dataRecord["op"] == 'ends') {
 					$content .= ".*".$searchterm."$";
 				}