Exchange Server OWA Change Login From DomainUsername to Username

Problem

In Exchange server environment, if you want to log into Outlook Web App, you need to use the DomainUsername format, like:

DomainUsername is not convenient for users. So you need to change the format to simply Username?

Solution

1️⃣ Log into the Exchange Admin Center > Servers > Virtual Directories > Locate OWA (Default WebSite) then double click on it to edit.

2️⃣ Select Authentication tab.

• Under Use Forms Based Authentication
• Select User name only option.
• Browse | Select your domain then save the changes.

3️⃣ Now on the server that’s hosting the OWA Website you need to Restart IIS (Internet Information Services).

[PS] C:\>iisreset.exe

Attempting stop...
Internet services successfully stopped
Attempting start...
Internet services successfully restarted

Finally, users can login into OWA using username only instead of DomainUsername.