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
@@ -102,6 +102,7 @@
 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, <<"* STATUS ", 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
@@ -115,25 +116,28 @@
     { add_response(Response, Acc), HasMore }.
 
 filter_on_details(#state{ blacklist = Blacklist }, Response, Acc, Details) ->
-    %% first determine if we have a quoted item or a non-quoted item and start from there
-    DetailsSize = byte_size(Details),
-    { Quoted, Start } = case binary:at(Details, DetailsSize - 1) of $" -> { quoted, DetailsSize - 2 }; _ -> { unquoted, DetailsSize - 1 } end,
-    Folder = find_folder_name(Details, Quoted, Start, Start, binary:at(Details, Start)),
-    %io:format("COMPARING ~p ??? ~p~n", [Folder, in_blacklist(Folder, Blacklist)]),
+    %% Remove "*" and extract response command name
+    { _, Start, _ } = pop_token(Response), %% asterisk
+    { Cmd, _, _ } = pop_token(Start), %% command
+
+    %% Extract folder name
+    Suffix =
+    case Cmd =:= <<"STATUS">> of
+        true -> Details;
+        _ ->
+            { Pos, _Length } = binary:match(Details, [<<")">>], []),
+            { _Delimiter, Rest, _} = pop_token(binary:part(Details, Pos + 2, byte_size(Details) - Pos - 2)),
+            Rest
+    end,
+    { Folder, _, _ } = pop_token(list_to_binary([Suffix, <<"\r\n">>])),
+
+    %% Check the folder in blacklist
+    %% io:format("COMPARING ~p ??? ~p~n", [Folder, in_blacklist(Folder, Blacklist)]),
     case in_blacklist(Folder, Blacklist) of
         true -> Acc;
         _ -> add_response(Response, Acc)
     end.
 
-find_folder_name(Details, quoted, End, Start, $") ->
-    binary:part(Details, Start + 1, End - Start);
-find_folder_name(Details, unquoted, End, Start, $ ) ->
-    binary:part(Details, Start + 1, End - Start);
-find_folder_name(Details, _Quoted, _End, 0, _) ->
-    Details;
-find_folder_name(Details, Quoted, End, Start, _) ->
-    find_folder_name(Details, Quoted, End, Start - 1, binary:at(Details, Start - 1)).
-
 add_response(Response, <<>>) -> Response;
 add_response(Response, Acc) -> <<Acc/binary, "\r\n", Response/binary>>.
 
@@ -147,3 +151,76 @@
                  _ -> in_blacklist(Folder, List)
              end
     end.
+
+%% pop_token from https://github.com/MainframeHQ/switchboard/blob/master/src/imap.erl (BSD Lic.)
+%% with some small changes by Aleksander Machniak <machniak@kolabsys.com>
+pop_token(Data) ->
+    pop_token(Data, none).
+
+pop_token(<<>>, State) ->
+    {none, <<>>, State};
+
+%% Consume hanging spaces
+pop_token(<<" ", Rest/binary>>, none) ->
+    pop_token(Rest, none);
+
+%% \r\n
+pop_token(<<$\r, $\n, Rest/binary>>, none) ->
+    {crlf, Rest, none};
+
+%% NIL
+pop_token(<<"NIL", Rest/binary>>, none) ->
+    {nil, Rest, none};
+
+%% ( | ) | [ | ]
+pop_token(<<$(, Rest/binary>>, none) ->
+    {'(', Rest, none};
+pop_token(<<$), Rest/binary>>, none) ->
+    {')', Rest, none};
+
+pop_token(<<$[, Rest/binary>>, none) ->
+    {'[', Rest, none};
+pop_token(<<$], Rest/binary>>, none) ->
+    {']', Rest, none};
+
+%% Atom
+pop_token(<<C, _/binary>> = Data, {atom, AtomAcc}) when
+  C =:= 32; C =:= 40; C =:= 41; C =:= $(; C =:= $); C =:= 91; C =:= 93 ->
+    {AtomAcc, Data, none};
+pop_token(<<$\r, $\n, _/binary>> = Data, {atom, AtomAcc}) ->
+    {AtomAcc, Data, none};
+pop_token(<<C, Rest/binary>>, none) when C >= 35, C < 123 ->
+    pop_token(Rest, {atom, <<C>>});
+pop_token(<<C, Rest/binary>>, {atom, AtomAcc}) when C >= 35, C < 123 ->
+    pop_token(Rest, {atom, <<AtomAcc/binary, C>>});
+
+%% Literal Strings
+pop_token(<<${, Rest/binary>>, none) ->
+    pop_token(Rest, {literal, <<>>});
+pop_token(<<$}, $\r, $\n, Rest/binary>>, {literal, ByteAcc}) ->
+    pop_token(Rest, {literal, binary_to_integer(ByteAcc), <<>>});
+pop_token(<<D, Rest/binary>>, {literal, ByteAcc}) when D >= 48, D < 58 ->
+    pop_token(Rest, {literal, <<ByteAcc/binary, D>>});
+pop_token(Binary, {literal, Bytes, LiteralAcc}) when is_integer(Bytes) ->
+    case Binary of
+        <<Literal:Bytes/binary, Rest/binary>> ->
+            {<<LiteralAcc/binary, Literal/binary>>, Rest, none};
+        _ ->
+            %% If the binary is too short, accumulate it in the state
+            pop_token(<<>>, {literal, Bytes - size(Binary), <<LiteralAcc/binary, Binary/binary>>})
+    end;
+
+%% Quoted Strings
+pop_token(<<$", Rest/binary>>, none) ->
+    pop_token(Rest, {quoted, <<>>});
+pop_token(<<$\\, C, Rest/binary>>, {quoted, Acc}) ->
+    pop_token(Rest, {quoted, <<Acc/binary, C>>});
+pop_token(<<$", Rest/binary>>, {quoted, Acc}) ->
+    {Acc, Rest, none};
+pop_token(<<$\r, $\n, _>>, {quoted, _}) ->
+    throw({error, crlf_in_quoted});
+pop_token(<<C, Rest/binary>>, {quoted, Acc}) ->
+    pop_token(Rest, {quoted, <<Acc/binary, C>>});
+
+pop_token(Binary, _) ->
+    {none, Binary, none}.