Im looking for that too..... I think crating a mailbox called *@domain.com then forwaring that mailbox to another one would to it.... Im gona try it 2night.
XFOR: Installing Internet Mail Service Extension Imsext.dll (Q258206)
In the WindowsNT Server, use regedit to go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeMTA\Parameters
Add a new string Value Name called "Journal Recipient Name"
and the Value Data is something like that /o=Watsons/ou=Hong Kong/cn=Recipients/cn=emailcopyaccount
Of course, you should create an email box called "emailcopyaccount" first.(emailcopyaccount is just a name, you could use your own name of it. Moreover, the word watsons and hong kong are only my settings, please change it as yours. P.S. I am not work in Watsons.)
Then all incoming emails of the whole company will go the the inbox, all outgoing emails will go the the sent items of the email box you created e.g. in the emailcopyaccount .
We use a product called eXclaimer for Exchange 2000. Allows addition of disclaimer information to all/selected emails as well as allowing for the copying of all/selected internal and/or external email for a domain to a seperate mailbox for monitoring purposes. Works very well! See http://www.exclaimer.co.uk