Dear All, I have exchange 2007 sp1, i need to login from OWA useing my public domain (User@mydomain.com) i can only login with the internal domain( user@mydomain.local) , any one can help Thanks

I am pretty sure that what Exchange 2007 supports is logging on with the user's UPN name, which frequently is different than their e-mail address. You first need to set up a UPN name suffix that matches your public SMTP. You do this on the properties of the Active Directory Domains and Trusts console. After you have created a new domain suffix for @yourdomain.com, n Active Directory Users and Computers, locate one of the users that want to logon with their e-mail address and change their UPN logon name to match their e-mail address. See if that fixes the issue.

Thanks a lot Jim , it works fine