exchange 5.5 mail recipients

This is a bit of a strange question:
I am trying to find a way (server based, not client based) to make alternate copies of mailboxes. I know with Exchange Admin I can also deliver incoming mail to an alternate recipient as well as the original recipient, but what about the sent mail? For example, say I want to monitor my mailbox I can create a second mailbox and select that a copy of all my incoming mail gets sent to this 2nd mailbox, but the mail I send is not tracked. Are there any options other than settting up a client side rule (rule or a BCC)? I would prefer something server based.
Thanks.