How to Configure Exchange to Receive email for other Domain names:

With Microsoft Exchange 2003, you can tell Exchange server to allow receiving mail for other domain names that the AD local domain.

To add a domain name:

1. Connect to the server where Exchange is installed.
2. Run "Exchange System Manager".
3. In the left side pane, Expand menu "Recipients".
4. Then "Recipients Policies".
5. In the right side pane, right-click "Default Policy" and select "Properties".
6. Clic on "E-Mail Addresses (Policy) and click the "New..." button.
7. From the "New E-Mail address" window, select "SMTP Address" and click "OK".
8. Position the cursor in the "Address" field and type in the domain name in this format: @newdomain.com
9. Make sure to leave the check mark next to "This Exchange Organization is responsible for all mail delivery to this address" and click "OK".
10. By default the new SMTP address will not be enabled. Click the check box nest to the newly added domain and click "OK"
11. The e-mail Addresses of type(s) [smtp] have been modified.
    Do you want to update all corresponding recipient e-mail addresses to match these new address(es)? Click yes if you want to ADD all Exchange users a new e-mail address corresponding to the @newdomain.com Click no if you want to manualy add e-mail addresses to selected accounts.