Dear Sir or Madam,I'm struggling with this one. I've searched the Web for hours and fooled around in Windows and Exchange for a solution but without any luck. I have a MS Windows 2003 Server 64 Bit Edition with MS Exchange 2007. The users got different e-mail address URLs.So, can Exchange handle for different URLs on one domain? If so, how is this done?Example:Server domain: AAAUser 1:Member of domain: AAAE-mail address: user1@123.comUser 2:Member of domain: AAAE-mail address: user2@xyz.comAny links to tutorials, tips, and help is highly appreciated!Yours faithfully,Pat. W.

Yes. open emc expand server config expand client access wait for the bottom right window top open right-click owa (default web site) select properties click the authentication tab select User Principal Name (UPN) from windows help: User principal name (UPN) If user principal name (UPN) logon format is specified, the User Name field on the OutlookWebAccess logon page guides the user to enter their e-mail address. For example, kweku@contoso.com. If a user's UPN is not identical to their e-mail address, the user cannot access OutlookWebAccess by using the PrincipalName logon prompt. We recommend that you do not use the PrincipalName logon prompt if users' UPNs do not match their e-mail addresses.