diff --git a/apps/kolab_guam/src/rules/kolab_guam_rule_filter_groupware.erl b/apps/kolab_guam/src/rules/kolab_guam_rule_filter_groupware.erl
--- a/apps/kolab_guam/src/rules/kolab_guam_rule_filter_groupware.erl
+++ b/apps/kolab_guam/src/rules/kolab_guam_rule_filter_groupware.erl
@@ -30,21 +30,21 @@
 
 apply_to_client_message(ImapSession, Buffer, State) ->
     { Tag, Command, Data } = eimap_utils:split_command_into_components(Buffer),
-    { Active, StateTag }=
-    if Command =:= <<"LIST">>;
-        Command =:= <<"list">>;
-        Command =:= <<"XLIST">>;
-        Command =:= <<"xlist">>;
-        Command =:= <<"LSUB">>;
-        Command =:= <<"lsub">> ->
-           case binary:match(Data, <<"*">>) of
-                nomatch -> { false, <<>> };
-                _ ->
-                   fetch_metadata(ImapSession, State),
-                   { true, Tag }
-           end;
-       true -> { false, <<>> }
-    end,
+    { Active, StateTag } =
+        if Command =:= <<"LIST">>;
+            Command =:= <<"list">>;
+            Command =:= <<"XLIST">>;
+            Command =:= <<"xlist">>;
+            Command =:= <<"LSUB">>;
+            Command =:= <<"lsub">> ->
+               case {binary:match(Data, <<"*">>),binary:match(Data, <<"%">>)} of
+                    nomatch -> { false, <<>> };
+                    _ ->
+                       fetch_metadata(ImapSession, State),
+                       { true, Tag }
+               end;
+           true -> { false, <<>> }
+        end,
     %lager:info("Client sent: ~s ~s ~p", [Command, Data, Active]),
     { Buffer, State#state{ active = Active, tag = StateTag }}.