How to forward all email to another account using OWA

To enable auto-forwarding of email within ESM:

1. Drill down in ESM into Global Settings or hub transport (exchange 2007)
2. Right-click on Internet Message Formats in the left pane.
3. Then double-click the Default format in the right pane.
4. Select the Advanced tab, and then verify that "Allow Automatic Forwards" is enabled.

 Message Format tab for remote domain properties

here in this link how to create e-mail fowarding rules in outlook web access

http://onlinehelp.hostbasket.com/shared-mailhosting/office-mail-exchange-2007/outlook-web-access-2007/990-manual-to-create-e-mail-forwarding-rules-in-outlook-web-access-2007-owa.html

 more about Managing Remote Domains setting in this link

http://technet.microsoft.com/en-us/library/aa996309.aspx