diff --git a/src/storage-rbox/rbox-sync-rebuild.cpp b/src/storage-rbox/rbox-sync-rebuild.cpp
index bd566fba..394df976 100644
--- a/src/storage-rbox/rbox-sync-rebuild.cpp
+++ b/src/storage-rbox/rbox-sync-rebuild.cpp
@@ -87,15 +87,28 @@ int rbox_sync_index_rebuild(struct index_rebuild_context *ctx, librados::NObject
   // find all objects with x attr M = mailbox_guid
   // if non is found : set mailbox_deleted and mail_storage_set_critical...
 
+  // it is required to check for duplicat uids,
+  // because if user moved / copied mails from mailbox to sub-mailbox,
+  // uid may stay the same (depends on configuration).
+  std::vector<std::string> uids;
+
   int found = 0;
   int ret = 0;
   while (iter != librados::NObjectIterator::__EndObjectIterator) {
     std::map<std::string, ceph::bufferlist> attrset;
     librmb::RadosMailObject mail_object;
     mail_object.set_oid((*iter).get_oid());
-
     int retx = r_storage->ms->get_storage()->load_metadata(&mail_object);
-
+    
+    /*std::string uid = mail_object->get_metadata(librmb::RBOX_METADATA_MAIL_UID);
+    
+
+    if(std::find(vector.begin(), vector.end(), uid) != vector.end(){
+      uids.put_back(uid);
+    }else{
+      // ups we have a duplicate!!!
+    }
+    */
     if (retx >= 0) {
       ret = rbox_sync_add_object(ctx, (*iter).get_oid(), &mail_object);
       if (ret < 0) {
diff --git a/src/tests/Makefile.am b/src/tests/Makefile.am
index 7db94c23..88c210eb 100644
--- a/src/tests/Makefile.am
+++ b/src/tests/Makefile.am
@@ -118,6 +118,11 @@ it_test_sync_rbox_2_SOURCES = sync-rbox/it_test_sync_rbox_2.cpp sync-rbox/TestCa
 it_test_sync_rbox_2_CPPFLAGS = $(AM_CPPFLAGS) $(LIBDOVECOT_INCLUDE) 
 it_test_sync_rbox_2_LDADD = $(storage_shlibs) $(gtest_shlibs) 
 
+TESTS += it_test_sync_rbox_duplicate_uid
+it_test_sync_rbox_duplicate_uid_SOURCES = sync-rbox/it_test_sync_rbox_duplicate_uid.cpp sync-rbox/TestCase.cpp sync-rbox/TestCase.h test-utils/it_utils.cpp test-utils/it_utils.h
+it_test_sync_rbox_duplicate_uid_CPPFLAGS = $(AM_CPPFLAGS) $(LIBDOVECOT_INCLUDE) 
+it_test_sync_rbox_duplicate_uid_LDADD = $(storage_shlibs) $(gtest_shlibs) 
+
 endif
 
 check_PROGRAMS = $(TESTS)