diff --git a/apps/kolab_guam/src/kolab_guam_session.erl b/apps/kolab_guam/src/kolab_guam_session.erl
--- a/apps/kolab_guam/src/kolab_guam_session.erl
+++ b/apps/kolab_guam/src/kolab_guam_session.erl
@@ -175,36 +175,6 @@
 close_socket(_ImplicitTLS, _TLS, Socket) -> gen_tcp:close(Socket).
 
 
-apply_rules(ImapSession, Socket, PreprocessData, CurrentCommandSplit, UndecidedRules, ActiveRules) ->
-    { ModifiedData, NewSplitCommand, NewSplitResetTrigger, NewUndecidedRules, NewActiveRules, PostAction } = apply_ruleset_clientside(ImapSession, Socket, PreprocessData, CurrentCommandSplit, UndecidedRules, ActiveRules),
-    BufferThisData =
-    case PostAction of
-        perform_passthrough ->
-            eimap:passthrough_data(ImapSession, ModifiedData),
-            <<>>;
-        buffer_data ->
-            % Originally Aaron uses Data here, but later on this buffer is assumed to be
-            % already decoded, so we do have to use PreprocessData here, I think.
-            case binary:matches(PreprocessData, <<"\r\n">>) of
-                [] ->
-                    lager:info("buffering: ~s", [PreprocessData]),
-                    PreprocessData;
-                List ->
-                    {FoundPos, _} = lists:last(List),
-                    % I would like to have some binary:match for the last instead of the
-                    % first occurrence; but I'm really inexperienced in erlang so I don't
-                    % know how to solve this efficiently, so I'm using binary:matches with
-                    % using the last element only
-                    SplitPos = FoundPos + 2,
-                    eimap:passthrough_data(ImapSession, binary:part(PreprocessData, 0, SplitPos)),
-                    lager:info("sending first part: ~s", [binary:part(PreprocessData, 0, SplitPos)] ),
-                    lager:info("buffering second part: ~s", [binary:part(PreprocessData, SplitPos, size(PreprocessData)-SplitPos)]),
-                    binary:part(PreprocessData, SplitPos, size(PreprocessData)-SplitPos)
-            end
-    end,
-    { NewUndecidedRules, NewActiveRules, BufferThisData, NewSplitCommand, NewSplitResetTrigger }.
-
-
 read_line(Data) ->
     case binary:match(Data, <<"\r\n">>) of
         nomatch ->
@@ -253,8 +223,15 @@
             eimap:compress(ImapSession), % TODO: make optional
             { TLS, Socket, NewInflator, NewDeflator, UndecidedRules, ActiveRules, <<>>, undefined, undefined };
         nochange ->
-            { NewUndecidedRules, NewActiveRules, BufferThisData, NewSplitCommand, NewSplitResetTrigger } =
-            apply_rules(ImapSession, Socket, Data, CurrentCommandSplit, UndecidedRules, ActiveRules),
+            { ModifiedData, NewSplitCommand, NewSplitResetTrigger, NewUndecidedRules, NewActiveRules, PostAction } = apply_ruleset_clientside(ImapSession, Socket, Data, CurrentCommandSplit, UndecidedRules, ActiveRules),
+            BufferThisData =
+            case PostAction of
+                perform_passthrough ->
+                    eimap:passthrough_data(ImapSession, ModifiedData),
+                    <<>>;
+                buffer_data ->
+                    Data
+            end,
             { TLS, Socket, Inflator, Deflator, NewUndecidedRules, NewActiveRules, BufferThisData, NewSplitCommand, NewSplitResetTrigger }
     end,
     set_socket_active(TLSActive, CurrentSocket),