Sometimes you are wondering how to enable the logon with out the domain\username.
Well there is a way to change this. You have to do the following.
First you have’t to go to the Exchange management Console
Go to the Server Configuration > Client Access
Select the Tab Outlook Web Access and click right to get the Properties option. Select Properties.
Go to the Tab Authentication.
Select Use Form-based Authentication > username Only > click on browse to select the domain name
After you have enter this settings click on OK and close the Exchange management Console.
Go to the web browser and type the web address of your outlook web access server.
You will be able to login with just only a username and password. No domain name is needed.