Use Exchange As Proxy For Gmail

I have a licensed copy of MS Exchange 2003 Server and a gmail account, and a licensed copy of Blackberry Enterprise Server Express , what I want to do is have the Exchange server send/receive email through my gmail account( using SMPT and POP3 protocol), put the mail in its local mailbox that I can then access through OWA and Outlook, and finally have the BESX server monitor the mailbox to synchronize it and my blackberry.

What I don’t want to have to do is host my own domain, which I have done in the past, but I am getting away from that ( shut down my old Exchange/BES setup last week ).

Thanks!