- Log in to the Exchange Control Panel. The default URL is: https://<server_name>.<domain_name>.com/ecp
- Go to servers > virtual directories.
- Select the owa entry, and then click the pencil icon (edit).
- Select authentication, and then select Use one or more standard authentication methods and Basic authentication.
- Select Save.
Outlook Web Access administration prompts to make the same change to the /ecp virtual folder.
Select the ecp entry and make the same setting changes as you did for the owa entry.