diff --git a/src/eimap_uidset.erl b/src/eimap_uidset.erl
index d48f79f..92776ec 100644
--- a/src/eimap_uidset.erl
+++ b/src/eimap_uidset.erl
@@ -1,78 +1,80 @@
 %% Copyright 2014 Kolab Systems AG (http://www.kolabsys.com)
 %%
 %% Aaron Seigo (Kolab Systems) <seigo a kolabsys.com>
 %%
 %% This program is free software: you can redistribute it and/or modify
 %% it under the terms of the GNU Library General Public License as published by
 %% the Free Software Foundation, either version 3 of the License, or
 %% (at your option) any later version.
 %%
 %% This program is distributed in the hope that it will be useful,
 %% but WITHOUT ANY WARRANTY; without even the implied warranty of
 %% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 %% GNU Library General Public License for more details.
 %%
 %% You should have received a copy of the GNU Library General Public License
 %% along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 -module(eimap_uidset).
--export([uid_list_to_binary/1, parse/1, next_uid/1]).
+-export([uid_list_to_binary/1, empty_uidset/0, parse/1, next_uid/1]).
 
 % for internal use only
 -export([add_uid_as_binary_to_list/2, stitch_bin_list/2]).
 
 %% tokens have the form: integer | { integer, integer }
 -record(uidset, { tokens = [], current = none }).
 
 uid_list_to_binary(UidList) when is_list(UidList) ->
     ListOfBins = lists:foldl(fun ?MODULE:add_uid_as_binary_to_list/2, [], UidList),
     lists:foldl(fun ?MODULE:stitch_bin_list/2, <<>>, ListOfBins);
 uid_list_to_binary(_UidList) -> <<>>.
 
 parse(UidSet) when is_list(UidSet) -> parse(list_to_binary(UidSet));
 parse(<<>>)  -> badarg;
 parse(UidSet) when is_binary(UidSet) ->
     Components = binary:split(UidSet, <<",">>, [global]),
     try lists:foldl(fun(Component, Acc) -> add_component(binary:split(Component, <<":">>), Acc) end, [], Components) of
         Parsed -> #uidset{ tokens = lists:reverse(Parsed) }
     catch
         _:_ -> badarg
     end.
 
+empty_uidset() -> #uidset{}.
+
 next_uid(#uidset{ tokens = Tokens, current = Current }) -> next_uid(Tokens, Current).
 next_uid([], _Current) -> { none, #uidset {} };
 next_uid([{ First, Second }|_] = FullList, Current) -> next_in_range(FullList, First, Second, Current);
 next_uid([Uid|UidSet], _Current) -> { Uid, #uidset{ tokens = UidSet } }.
 
 % PRIVATE API
 add_uid_as_binary_to_list(Uid, Acc) when is_integer(Uid), Uid >= 0 -> [integer_to_binary(Uid)|Acc];
 add_uid_as_binary_to_list({ StartUid, EndUid }, Acc) when is_integer(StartUid), is_integer(EndUid) ->
     case add_uid_range_as_binary_to_list(StartUid, EndUid) of
         error -> Acc;
         { Start, End } -> [<<Start/binary, ":", End/binary>>|Acc]
     end;
 add_uid_as_binary_to_list(_, Acc) -> Acc.
 
 add_uid_range_as_binary_to_list(Start, End) when Start < 0; End < 0 -> error;
 add_uid_range_as_binary_to_list(Start, End) when Start < End -> { integer_to_binary(Start), integer_to_binary(End) };
 add_uid_range_as_binary_to_list(Start, End) -> { integer_to_binary(End), integer_to_binary(Start) }.
 
 stitch_bin_list(Uid, <<>>) -> Uid;
 stitch_bin_list(Uid, Acc) -> <<Uid/binary, ",", Acc/binary>>.
 
 add_component(Uid, Acc) when is_integer(Uid), Uid >= 0 -> [Uid|Acc];
 add_component([First, Second], Acc) -> add_component(binary_to_integer(First), binary_to_integer(Second), Acc);
 add_component([<<"">>], Acc) -> Acc;
 add_component([Single], Acc) when is_binary(Single) -> add_component(binary_to_integer(Single), Acc);
 add_component(_, _Acc) -> throw(badarg).
 
 add_component(First, Second, Acc) when is_integer(First), First >= 0, is_integer(Second), Second >= 0 -> add_range(First, Second, Acc);
 add_component(_, _, _Acc) -> throw(badarg).
 
 add_range(First, Second, Acc) when First == Second -> [First|Acc];
 add_range(First, Second, Acc) -> [{ First, Second }|Acc].
 
 next_in_range(Tokens, First, _Second, none) -> { First, #uidset{ tokens = Tokens, current = First } };
 next_in_range(Tokens, First, Second, Current) when First < Second, Current < Second -> Next = Current + 1, { Next, #uidset{ tokens = Tokens, current = Next } };
 next_in_range(Tokens, First, Second, Current) when First > Second, Current > Second -> Next = Current - 1, { Next, #uidset{ tokens = Tokens, current = Next } };
 next_in_range([_|Tokens], _First, _Second, _Current) -> next_uid(#uidset{ tokens = Tokens }).