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
@@ -31,8 +31,13 @@
 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">> ->
-           case binary:match(Data, <<"\"*\"">>) of
+    if Command =:= <<"LIST">>;
+        Command =:= <<"list">>;
+        Command =:= <<"XLIST">>;
+        Command =:= <<"xlist">>;
+        Command =:= <<"LSUB">>;
+        Command =:= <<"lsub">> ->
+           case binary:match(Data, <<"*">>) of
                 nomatch -> { false, <<>> };
                 _ ->
                    fetch_metadata(ImapSession, State),
@@ -65,10 +70,14 @@
     true;
 apply_if_id_matches(<<"XLIST">>, _Data) ->
     true;
+apply_if_id_matches(<<"LSUB">>, _Data) ->
+    true;
 apply_if_id_matches(<<"list">>, _Data) ->
     true;
 apply_if_id_matches(<<"xlist">>, _Data) ->
     true;
+apply_if_id_matches(<<"lsub">>, _Data) ->
+    true;
 apply_if_id_matches(<<"ID">>, Data) ->
     apply_if_found_kolab(binary:match(Data, <<"/Kolab">>));
 apply_if_id_matches(_Command, _Data) -> notyet.
@@ -93,6 +102,7 @@
 filter_folder(_State, <<>>, Acc) -> { Acc, true };
 filter_folder(State, <<"* LIST ", Details/binary>> = Response, Acc) -> { filter_on_details(State, Response, Acc, Details), true };
 filter_folder(State, <<"* XLIST ", Details/binary>> = Response, Acc) -> { filter_on_details(State, Response, Acc, Details), true };
+filter_folder(State, <<"* LSUB ", Details/binary>> = Response, Acc) -> { filter_on_details(State, Response, Acc, Details), true };
 filter_folder(#state{ tag = Tag }, Response, Acc) ->
     HasMore =
     case byte_size(Tag) =< byte_size(Response) of