About Exchange

Hi,

I have three questions on Exchange 5.5:
1) What is the use of X400 in Exchange 5.5
2) What is the use of CCMAIL
3) I blocked so many adult emails in message filtering but still my users are getting adult emails is there any way to block them is there any script which I run on my users pc and it stops all adult and other useless emails.
I would appreciate if someone could assist me on this.
Thanks and Regards.
Anurag.