Outbound Messages in MS Exchange 5.5

Hi Everyone,

I m using MS Exchange 5.5 and i required to copy all outgoing mail from my SMTP Server to any mailbox just becoz to check employees out going messages isnt harm for our company. Is this possible in Exchange 5.5?? if yes then do guide me or if it is possible by third party tool

Thanx Indeed
Regards,
zaxs