Set up Exchange 2000 to host multiple domains

Dear all,
I have install Exchange 2000 server in Windows 2000 server. My domain controller is Test.com , I add 2 domain (ABC.COM and XYZ.COM) . User of ABC.COM, XYZ.COM can send/receive mail but They can’t not logon to domain by OutLook Web Access . user of Test.com can logon to domain. How to logon to ABC.COM, XYZ.COM , please help me

Thanks in advance!

Dunhill