Try this link

http://www.microsoft.com/exchange/partners/archivingandcompliance.asp

Thanks Andrew

Found this product,and after setting up 2 custom rules
it works well,

I'm on the 30 day trail but for a $130.00 u.s it's pretty cheap

http://exclaimer.com/

You want to take a look at products that provide internal and outbound content
control for Exchange Server. These are not archival products as
internal/outbound control products provide real time monitoring and prevention
of content violations.  Many support only Exchange 2003 or Exchange 2000, but
some do support Exchange 5.5 as well

SecurExchange Corporate (which I represent) has the capability to monitor and
take various actions in real time (and block if need be) based on content,
mailbox, etc.    

See www.nemx.com/products/SecurExchange