How to Change OWA Logon Option in Exchange Server 2013 ~ System Help Line

The default logon option in OWA is using the format : Domain\username as shown in the below snapshot

You can change the default logon format to one of the following formats:

username@domainname.tld
Username

So lets check how to change the OWA logon format in Exchange Server 2013 :

Login into Exchange Admin Center and then from the left side menu, click on servers
Click on virtual directories
From the list of the available virtual directories, click on the owa (Default Web Site) and then click on the edit button
The owa virtual directory options page will open, from the left side menu, click on authentication
As you can see, three forms-based authentication logon formats are available

Domain\user name
User prinicipal name (UPN)
User name only

The default option is the Domain\user name , to set it to logging in using your complete email ID , then select User principal name (IPN) and click on save

To apply the changes, you must restart IIS .

Note : Check the steps at the end of this article to know how to restart IIS.
After IIS is restarted, the logon format will be as shown below. My email ID is tarek.majdalani@elmajdal.com so I will login into OWA using tarek.majdalani@elmajdal.com instead of elmajdal\tarek.majdalani
To Set the logon format to username only, select User name only

Then select the domain name by clicking on browse... and from the list of available domains, select the domain you want to authenticate your users from then click ok

The domain name will be selected, click save to set the forms-based authentication format option to be username only.

Of course, you must restart IIS to apply the changes

After IIS is restarted, the next time you try to logon, you will be presented with the username only logon format as shown below