*** Updated by Wrobinson on 02/29/08 ***
You can configure each mailbox to forward a copy of all messages to another mailbox. To do so for archiving purposes, the best way to accomplish this would be to set up a new mailbox for each user solely for the purpose of collecting all messages received. Then you can subsequently archive these messages by downloading them using POP, etc.
It is not possible in Exchange 200x to have more than one mailbox per user object.
*** End Update ***
I’ll assume you mean one of two things:
1. An exchange server and user…
You can create another mailbox (with a different address) and assign that user with rights to the
mailbox, but you cannot create a second “inbox” on a user’s mailbox.
2. Using outlook as a POP3 client.
You can create a second “account” with a different ISP in outlook that delivers to a new PST file.