Question about Outlook Express

I wish to block unsolicited messages from messenger, people who are not on my contact list or ever been on my contact list. I understand that people not on contact list are supposedly unable to send messages since I am using 2011 Live version, but this has clearly failed miserably as everyone I know gets unsolicited messages from various people using various other IM systems. Reporting abuse has no effect. These people need to have their ISP address blocked, not just their account, otherwise they simply create another account name. It is your responsibility to keep spammers and abusers out of your messenger system and you seem little inclined to do so, indeed, several people have asked this question on different forums including your own, and yet no adequate response has been given by your company. This is appalling lack of service.