[otrs] filtering spam

Hi there, I have MANY messages with only question marks. HOW can I filter them with the generic agent? When inserting a question mark, it filters ALL messages!! The mails are like this one: ___________ ?? ????? ? ??????? ????? ???????? - ?????? ???? ?????????, ? ??? ?????????? ???????? ???? ??????????? ?????? ? ???????? ???????????. ???? ???? ????, ??? ? ???????????. ?? ?????? ??????? ? ???????????? ???????. ?????o? ? ?oc???: (495) 649-86-27 ?????o? ? ?a???-????p??p??: (812) 313-23-91 ICQ: 590-644-122 ____________ how can I filter them to be deleted? thanks, marc