Please tell us the version of Exchange and the antispam/antivirus software installed on it.
Looks like your “question” saying your exchange version was 2003 and antivirus was norton 2002 was deleted.
Exchange 2003 and norton 2002 do not have antispam features, so with your current configuration you are not capable of blocking email, no. Try getting the symantec exchange email protect and then you can control that. Your ISP may be blocking at their level, try calling your internet provider and ask.