Multiple Mailboxes in Exchange

We have SB2004 installed with exchange. We also have a generic email address like sales@mydomain.com. This is usually accessed by 2 users who also have individual email addresses - user1@mydomain.com and user2@mydomain.com. Both users were accessing this email in Outlook before exchange was installed. Whoever of the 2 users could reply to any incoming email would do so and cc to the other user to keep him in the loop.
Now that we have exchange  we have created 3 mailboxes  in Exchange - sales, user1 and user2 which are mapped to the appropriate pop mailboxes.
User1 & User2 have both been given full permission to the sales mailbox. In outlook for each of these users the additinal mailbox - sales has been added. Hence both users can in their outlook see their individual mailboxes as well as the generic sales mailbox. They can then also see if the mail has been read or not.

Is this is the most appropriate way of handling this situation ?

My second question is - one user uses a MacBook and has Entourage installed. We cannot get Entourage to work with the Exchange server even though OWA works from the MAc. Could somebody help us ? Additinally if we get entourage or the built in Mac Mail application to work with Exchange, would that support the additional mailbox so that user1 can see his mailbox as well as the sales mailbox on his mac.

Any help would be great.