Return addresses on Outlook

I have yet another problem to tackle .

We are running Exchange 2003 on a Windows Server 2003 server with active directory.  Our users run either Windows 2000 or Windows xp using either Outlook 2000 or 2003.

I have been asked to get mailbox x to forward all incomming mail to mailboxes a, b, c & d. That part I can do at the server end of things.

I am to set up things so that when the users reply to the emails, their replies will appear as to have come from mailbox x, where the customers originally sent them to. This is the bit I cannot figure out how to do.

Please can anyone help?

Thanks

I'm not aware that any active forum members have expertise in Exchange, but I could be wrong.  I found two sites you might visit:

http://technet.microsoft.com/en-us/library/bb123872.aspx

http://support.microsoft.com/exch2003